https://hdl.handle.net/1721.1/97456 Tue, 21 Apr 2026 10:37:50 GMT 2026-04-21T10:37:50Z https://hdl.handle.net/1721.1/103032 Deployment of Analytics into the Healthcare Safety Net: Lessons Learned & Unlearned Hartzband, David In October of 2013, I made a proposal to the RCHN Community Health Foundation to start a project that would deploy a contemporary analytic software capability into community health centers that volunteered for the project & to work with their IT & executive staffs so that the capability could be productively used as part of how the health center made strategic decisions . I wrote at the time: “Everyone agrees that “analytics” are/will be important for community health centers as they evolve to new organizational (participants HIEs, ACOs, HCCNs etc.) & sustainability (service providers, data providers) models. What this means & how to do it are hotly discussed topics, however, with no apparent tactic or strategy that seems feasible. There is no big bang in this effort. This capability will not spring forth complete & productive if health centers make the correct invocation or even spend a large amount of money. This memo specifies a program that would pilot an actual path for health centers (& other healthcare organizations with limited resources) to follow to begin to productively use analytics & to evolve a more & more effective capability in this area.” I also wrote that: “Complex analytics, multi-layered analytics and highly designed data warehouses are not necessary, and moreover, not appropriate if the questions that are asked aren’t relevant or don’t require them and the underlying data isn’t complete and reliable." That was just over two years ago. What happened with the project & what is going on with it now? What lessons have been learned? What lessons did we already know but needed to have reinforced by painful experience? Here is a project update. Tue, 01 Dec 2015 00:00:00 GMT https://hdl.handle.net/1721.1/103032 2015-12-01T00:00:00Z https://hdl.handle.net/1721.1/103031 Inter-airline Equity in Airport Scheduling Interventions Jacquillat, Alexandre; Vaze, Vikrant In the absence of opportunities for capacity expansion or operational enhancements, air traffic congestion mitigation may require scheduling interventions aimed to control the extent of overcapacity scheduling at busy airports. Previous research has shown that large delay reductions could be achieved through comparatively small changes in the schedule of flights. While existing approaches have focused on minimizing the overall impact of scheduling interventions across the airlines, this paper designs, optimizes, and assesses a novel approach for airport scheduling interventions that incorporates inter-airline equity objectives. It relies on a lexicographic modeling architecture based on efficiency (i.e., meeting airline scheduling preferences), equity (i.e., balancing scheduling adjustments fairly among the airlines), and on-time performance (i.e., mitigating airport congestion) objectives, subject to scheduling and network connectivity constraints. Theoretical results show that, under some scheduling conditions, equity and efficiency can be jointly maximized. Computational results suggest that, under a wide range of current and hypothetical scheduling settings, ignoring inter-airline equity can lead to highly inequitable outcomes, but that our modeling approach achieves inter-airline equity at no, or small, losses in efficiency. Keywords: airport demand management, inter-airline equity, efficiency-equity trade-off, integer programming, dynamic programming, queuing model Tue, 01 Sep 2015 00:00:00 GMT https://hdl.handle.net/1721.1/103031 2015-09-01T00:00:00Z https://hdl.handle.net/1721.1/103030 Challenges and Opportunities in Implementation of the Future California Rail Network Levy, Samuel; Faulkner, A. Awadagin; Sussman, Joseph M. The California High-Speed Rail Authority (CHSRA) adopted a "blended system" at the northern and southern termini of the planned first phase of its high-speed rail line. In this blended operation, the high-speed rail line will share track and other infrastructure with commuter, intercity, and freight rail. However, the lack of common infrastructure among rail modes and the financial and organizational challenges associated with building that common infrastructure and capacity allocation in California present challenges for the implementation of high-speed rail via a blended system in the state. This paper reviews the blended system and discusses the level of cooperation and coordination necessary between host railroads/agencies and the high-speed rail tenant operator. Sharing track comes with challenges for all participating railroad operators and often requires coordination between heterogeneous rail traffic. However, costs can be reduced compared to dedicated track. How blended service is carried out will impact state and local agencies, railroad owners and operators, and customers across the California rail network. Sat, 01 Aug 2015 00:00:00 GMT https://hdl.handle.net/1721.1/103030 2015-08-01T00:00:00Z https://hdl.handle.net/1721.1/103029 Energy Resource Transportation Governance: Case Studies of The Alberta Oil Sands and The Argentinian Vaca Muerta Shale Oil Fields Agosta, Bruno; Carlson, S. Joel; Sussman, Joseph M. In recent years, there has been increasing focus on the economic and other benefits of the development of “unconventional” sources of oil—resources that cannot be produced using traditional production techniques—partly due to the increased scarcity of conventional oil reserves. This paper compares and contrasts unconventional oil resources in Canada and Argentina. Canada has deposits of bitumen known as oil sands/tar sands. Bitumen is “a thick, sticky form of crude oil that is so heavy and viscous that it will not flow unless it is heated or diluted with lighter hydrocarbons” (Government of Alberta 2009), and when mixed with sand and clay, is known as the oil sands. In Argentina there are shale oil formations, which is crude oil found in low-permeability rock formations. The unconventional hydrocarbons in Canada (the oil sands) and Argentina (shale oil) are significant resources for both countries, especially when compared with their conventional reserves. Though the institutional structure is different in both countries—Canada’s oil and gas and transportation companies are privately-owned, whereas in Argentina, they are partially government owned—the rhetoric of the discussions seems to be similar in both countries: many are in favor of development due to the significance of the economic benefits. However, in both countries, the development of transport infrastructure has been hindered by different factors, on environmental grounds, notably with regard to concerns regarding greenhouse gas emissions (in Canada) and lacking sufficient planning capabilities and institutional framework for long-term investments such as railroads (in Argentina). Sat, 01 Aug 2015 00:00:00 GMT https://hdl.handle.net/1721.1/103029 2015-08-01T00:00:00Z https://hdl.handle.net/1721.1/103028 DRAFT Model Brokerage: Concepts & A Proposal Hartzband, David Effective & efficient utilization of models is essential for facilitating high productivity in many different types of organizations. If models could be shared across technical, temporal & organizational boundaries, much higher productivity could be realized. This would also be true if models could be combined in effective ways. This work presents a result from model theory showing that for complex models, a small number of axioms (true statements of the models contents) can be used as a representation of the entire model. An analogy with multivariate analysis shows that this small set of axioms can be shown to contain the majority of the information in the model. The implication is that much simpler models could be used for descriptive & predictive analysis, making these processes easier to compute & to understand. Mon, 01 Jun 2015 00:00:00 GMT https://hdl.handle.net/1721.1/103028 2015-06-01T00:00:00Z https://hdl.handle.net/1721.1/103027 A Cubic Framework for the Chief Data Officer: Succeeding in a World of Big Data Lee, Yang; Madnick, Stuart E.; Wang, Richard Y.; Wang, Forea; Zhang, Hongyun A new breed of executive, the chief data officer (CDO), is emerging as a key leader in the organization. We provide a three-dimensional cubic framework that describes the role of the CDO. The three dimensions are: (1) Collaboration Direction (inwards vs. outwards), (2) Data Space (traditional data vs. big data) and (3) Value Impact (service vs. strategy). We illustrate the framework with examples from early adopters of the CDO role and provide recommendations to help organizations assess and strategize the establishment of their own CDOs. Sat, 01 Nov 2014 00:00:00 GMT https://hdl.handle.net/1721.1/103027 2014-11-01T00:00:00Z https://hdl.handle.net/1721.1/103026 Institutional Foundations for Cyber Security: Current Responses and New Challenges Choucri, Nazli; Madnick, Stuart E.; Ferwerda, Jeremy Almost everyone recognizes the salience of cyberspace as a fact of daily life. Given its ubiquity, scale, and scope, cyberspace has become a fundamental feature of the world we live in and has created a new reality for almost everyone in the developed world and increasingly for people in the developing world. This paper seeks to provide an initial baseline, for representing and tracking institutional responses to a rapidly changing international landscape, real as well as virtual. We shall argue that the current institutional landscape managing security issues in the cyber domain has developed in major ways, but that it is still “under construction.” We also expect institutions for cyber security to support and reinforce the contributions of information technology to the development process. We begin with (a) highlights of international institutional theory and an empirical “census” of the institutions-in-place for cyber security, and then turn to (b) key imperatives of information technology-development linkages and the various cyber processes that enhance developmental processes, (c) major institutional responses to cyber threats and cyber crime as well as select international and national policy postures so critical for industrial countries and increasingly for developing states as well, and (d) the salience of new mechanisms designed specifically in response to cyber threats. Sat, 01 Nov 2014 00:00:00 GMT https://hdl.handle.net/1721.1/103026 2014-11-01T00:00:00Z https://hdl.handle.net/1721.1/103025 Using System Dynamics to Analyze the Effect of Funding Fluctuation on Software Development Trammell, Travis; Madnick, Stuart E.; Moulton, Allen Almost everyone understands that budget fluctuations have an impact on software development, but it is difficult to estimate the magnitude of the impact and all the causes. This paper uses System Dynamics modeling to examine how gaps in funding affect software development productivity and product delivery delay. The results provide decision makers with an improved sense of the negative impacts of budget fluctuations. Two key insights include the “ramp up tax” that slows development and the “gap tax” due to the loss of project-related skill and familiarity when employees are transferred off of a project and then return. The model experiments also compare the different impacts of temporarily stopping a project versus stretching out a project by temporarily reducing the funding level. Wed, 01 Oct 2014 00:00:00 GMT https://hdl.handle.net/1721.1/103025 2014-10-01T00:00:00Z https://hdl.handle.net/1721.1/103024 Agile Project Dynamics: A System Dynamics Investigation of Agile Software Development Methods Glaiel, Firas S.; Moulton, Allen; Madnick, Stuart E. While Agile software development has many advocates, acceptance in the government and defense sectors has been limited. To address questions of meanings to the term “Agile,” we examine a range of Agile methods practiced and develop a framework of seven characteristics, which we call the Agile Genome. We gain insight into the dynamics of how Agile development compares to classic “waterfall” approaches by constructing a System Dynamics model for software projects. The Agile Project Dynamics (APD) model captures each of the Agile genes as a separate component of the model and allows experimentation with combinations of practices and management policies. Experimentation with the APD model is used to explore how different genes work in combination with one another to produce both positive and negative effects. The extensible design of the APD model provides the basis for further study of Agile methods and management practices. Wed, 01 Oct 2014 00:00:00 GMT https://hdl.handle.net/1721.1/103024 2014-10-01T00:00:00Z https://hdl.handle.net/1721.1/103023 STEM Crisis or STEM Surplus? Yes and Yes Xue, Yi; Larson, Richard Charles Over the last decade, there has been significant concern regarding a shortage of science, technology, engineering, and mathematics (STEM) workers to meet the demands of the labor market. At the same time, many experts have presented evidence of a STEM worker surplus. The literature tends to lean heavily in one direction or the other: one side proclaims an impending STEM crisis and the other side asserts a STEM surplus. This paper tries to reconcile the “STEM Crisis” vs. “STEM Surplus” debate by segmenting the STEM labor market into different industries, occupations, and skill levels. We conduct an in-depth analysis of the STEM labor market using a comprehensive literature review in conjunction with sources such as employment statistics, newspaper articles, and authors’ interviews with company recruiters. Our findings indicate a significant heterogeneity in the STEM labor market. While the academic sector is generally oversupplied, the government and government-related sector has shortages in specific areas such as nuclear engineering, materials science, and electrical engineering, as well as cybersecurity and intelligence. The private sector also has specific shortages for positions such as petroleum engineers, data scientists, and software developers. At the same time, there are surpluses for graduates in areas such as chemistry and physics. The demand and supply also vary according to location and U.S. citizenship. Based on our analysis, we discuss policies to address the STEM workforce demand and supply. Wed, 01 Oct 2014 00:00:00 GMT https://hdl.handle.net/1721.1/103023 2014-10-01T00:00:00Z https://hdl.handle.net/1721.1/103022 A Unified Approach for Taxonomy-based Technology Forecasting Henschel, Andreas; Casagrande, Erik; Woon, Wei Lee; Janajreh, Isam; Madnick, Stuart E. For decision makers and researchers working in a technical domain, understanding the state of their area of interest is of the highest importance. For this reason, we consider in this chapter, a novel framework for Web-based technology forecasting using bibliometrics (i.e. the analysis of information from trends and patterns of scientific publications). The proposed framework consists of a few conceptual stages based on a data acquisition process from bibliographic online repositories: extraction of domainrelevant keywords, the generation of taxonomy of the research field of interests and the development of early growth indicators which helps to find interesting technologies in their first phase of development. To provide a concrete application domain for developing and testing our tools, we conducted a case study in the field of renewable energy and in particular one of its subfields: Waste-to-Energy (W2E). The results on this particular research domain confirm the benefit of our approach. Fri, 01 Aug 2014 00:00:00 GMT https://hdl.handle.net/1721.1/103022 2014-08-01T00:00:00Z https://hdl.handle.net/1721.1/103021 Towards better understanding Cybersecurity: Or are "Cyberspace" and "Cyber Space" the same? Madnick, Stuart E.; Choucri, Nazli; Camina, Steven; Woon, Wei Lee Although there are many technology challenges and approaches to attaining cybersecurity, human actions (or inactions) also often pose large risks. There are many reasons, but one problem is whether we all “see the world” the same way. That is, what does “cybersecurity” actually mean – as well as the many related concepts, such as “cyberthreat,” “cybercrime,” etc. Although dictionaries, glossaries, and other sources tell you what words/phrases are supposed to mean (somewhat complicated by the fact that they often contradict each other), they do not tell you how people are actually using them. If we are to have an effective solution, it is important that all the parties understand each other – or, at least, understand that there are different perspectives. For the purpose of this paper and to demonstrate our methodology, we consider the case of the words, “cyberspace” and “cyber space.” When we started, we assumed that “cyberspace” and “cyber space” were essentially the same word with just a minor variation in punctuation (i.e., the space, or lack thereof, between “cyber” and “space”) and that the choice of the punctuation was a rather random occurrence. With that assumption in mind, we would expect that the usage of these words (as determined by the taxonomies that would be constructed by our algorithms) would be basically the same. As it turned out, they were quite different, both in overall shape and groupings within the taxonomy. Since the overall field of cybersecurity is so new, understanding the field and how people think about it (as evidenced by their actual usage of terminology, and how usage changes over time) is an important goal. Our approach helps to illuminate these understandings. Wed, 01 Oct 2014 00:00:00 GMT https://hdl.handle.net/1721.1/103021 2014-10-01T00:00:00Z https://hdl.handle.net/1721.1/103020 Quantitative Determination Of Technological Improvement From Patent Data Benson, Christopher L.; Magee, Christopher L. The results in this paper establish that information contained in patents in a technological domain is strongly correlated with the rate of technological progress in that domain. The importance of patents in a domain, the recency of patents in a domain and the immediacy of patents in a domain are all strongly correlated with increases in the rate of performance improvement in the domain of interest. A patent metric that combines importance and immediacy is not only highly correlated (r = 0.76, p = 1.12*10-5) with the performance improvement rate but the correlation is also very robust to domain selection and appears to have good predictive power for more than ten years into the future. Linear regressions with all three causal concepts indicate realistic value in practical use to estimate the important performance improvement rate of a technological domain. Wed, 01 Oct 2014 00:00:00 GMT https://hdl.handle.net/1721.1/103020 2014-10-01T00:00:00Z https://hdl.handle.net/1721.1/103019 Striving for Safety: Communicating and Deciding in Sociotechnical Systems Flach, John M.; Carroll, John Stephen; Dainoff, Marvin J.; Hamilton, W. Ian How do communications and decisions impact the safety of sociotechnical systems? This paper frames this question in the context of a dynamic system of nested sub-systems. Communications are related to the construct of observability (i.e., how components integrate information to assess the state with respect to local and global constraints). Decisions are related to the construct of controllability (i.e., how component sub-systems act to meet local and global safety goals). The safety dynamics of sociotechnical systems are evaluated as a function of the coupling between observability and controllability across multiple closed-loop components. Two very different domains (nuclear power and the limited service food industry) provide examples to illustrate how this framework might be applied. While the dynamical systems framework does not offer simple prescriptions for achieving safety, it does provide guides for exploring specific systems to consider the potential fit between organisational structures and work demands, and for generalizing across different systems regarding how safety can be managed. Mon, 01 Sep 2014 00:00:00 GMT https://hdl.handle.net/1721.1/103019 2014-09-01T00:00:00Z https://hdl.handle.net/1721.1/103018 Analyzing the Financial Relationship between Railway Industry Players in Shared Railway Systems: The Train Operator’s Perspective Levy, Sam; Pena-Alcaraz, Maite; Prodan, Aleksandr; Sussman, Joseph M. Capacity pricing and allocation play an important role in efficient management of railway corridors, especially shared ones. This paper analyzes how Train Operators (TOs) would respond to different track-access charges, as a first step to understand the relationship between Train Operators and Infrastructure Manger (IM) in railway systems with some level of vertical separation. By modeling a corridor whose users are long-distance high-speed trains and freight trains along the entire corridor, and commuter trains offering services around large urban areas in the corridor, this paper narrows down the focus on each individual operator, looking at the factors that drive each operator's ultimate service levels. Assuming an environment where the TOs are competing for capacity, financial goals and boundary conditions of each TO are derived, and a number of sensitivity analyses for various typical and extreme conditions are performed. This model allows to anticipate how TOs would respond to track-access charges, and can thus help the government, the regulators, and the IMs in the design of appropriate capacity pricing and allocation schemes. Fri, 01 Aug 2014 00:00:00 GMT https://hdl.handle.net/1721.1/103018 2014-08-01T00:00:00Z https://hdl.handle.net/1721.1/103017 HSR as Transit: The continuing transportation-driven evolution of metropolitan form Westrom, Ryan J.; Sussman, Joseph M. With high-speed rail (HSR) now often fulfilling a commuting function within an hour’s travel time from principal metropolitan cities, it becomes the latest in a long line of transportation technologies to elicit change in the metropolitan form of these cities. This paper explores this history, and then the potential for this shifting form in the era of HSR. Viewing HSR as transit, its ramifications on metropolitan form are reviewed. Via a closer look at four case cities home to potential future HSR systems—Coimbra and Leiria in Portugal and Champaign-Urbana and Kankakee in Illinois within the U.S.A.—that will move within a principal city’s commuting reach—Lisbon and Chicago, respectively-implications for transportation and land use planning are discussed. The unique discontinuous nature of these new potential forms presents fresh opportunities to implement planning best practices, providing sustainability and quality of life returns. These speak well to the potential for HSR to serve this new function, and provide support for the consideration of HSR as a transportation alternative for these settings. Fri, 01 Aug 2014 00:00:00 GMT https://hdl.handle.net/1721.1/103017 2014-08-01T00:00:00Z https://hdl.handle.net/1721.1/103016 Technology Structural Implications from the Extension of a Patent Search Method Benson, Christopher L.; Magee, Christopher L. Many areas of academic and industrial work make use of the notion of a ‘technology’. This paper attempts to reduce the ambiguity around the definition of what constitutes a ‘technology’ by extension of a method described previously that finds highly relevant patent sets for specified technological fields. The method relies on a less ambiguous definition that includes both a functional component and a component consisting of the underlying knowledge in a technological field to form a two-component definition. These two components form a useful definition of a technology that allows for objective, repeatable and thus comparable analysis of specific technologies. 28 technological domains are investigated: the extension of an earlier technique is shown to be capable of finding highly relevant and complete patent sets for each of the technologies. Overall, about 500,000 patents from 1976 to 2012 are classified into these 28 domains. The patents in each of these sets are not only highly relevant to the domain of interest but there are relatively low numbers of patents classified into any two of these domains (total patents classified in 2 domains are 2.9% of the total patents and the great majority of patent class pairs have zero overlap with a few of the 378 patent class pairs containing the bulk of the doubly listed patents). On the other hand, the patents within a given domain cite patents in other domains about 90% of the time. These results suggest that technology can be usefully decomposed to distinct units but that the inventions in these relatively tightly contained units depend upon widely spread additional knowledge. Tue, 01 Jul 2014 00:00:00 GMT https://hdl.handle.net/1721.1/103016 2014-07-01T00:00:00Z https://hdl.handle.net/1721.1/103015 Quantitative empirical trends in technical performance Magee, Christopher L.; Basnet, Subarna; Funk, Jeffrey L.; Benson, Christopher L. Technological improvement trends such as Moore’s law and experience curves have been widely used to understand how technologies change over time and to forecast the future through extrapolation. Such studies can also potentially provide a deeper understanding of R&D management and strategic issues associated with technical change. However, this requires that methodological approaches for these analyses be addressed and compared to more effectively interpret results. Our analysis of methodological issues recommends less ambiguous approaches to: 1) the unit of analysis; 2) choice of the metrics within a unit of analysis; 3) the relationships among possible independent variables; and 4) qualitative and quantitative data quality considerations. The paper then uses this methodology to analyze performance trends for 28 technological domains with the following findings: 1. Sahal’s relationship is tested for several effort variables (for patents and revenue in addition to cumulative production where it was first developed). 2. The relationship is quite accurate when all three relationships, ( a. an exponential between performance and time, b. an exponential of effort and time and c. a power law between performance and the effort variable) have good data fits (r2 >0.7) . 3. The power law and effort exponents determined are dependent upon the choice of effort variable but the time dependence exponential is not. 4. In domains where the quantity of patents do not increase exponentially with time, Sahal’s relationship gives poor estimates even though Moore’s law is followed even for these domains. 5. Good data quality for any of the relationships depends upon adequate screening involving not only r2 but also the confidence interval based upon two different statistical tests; by these measures, all 28 domains have high quality fits between the log of performance and time whereas less than ½ show this level of quality for power law fits with patents as the effort variable. Overall, the results are interpreted as indicating that Moore’s law is a better description of longer-term technological change when the performance data come from various designs whereas experience curves may be more relevant when a singular design in a given factory is considered. Tue, 01 Jul 2014 00:00:00 GMT https://hdl.handle.net/1721.1/103015 2014-07-01T00:00:00Z https://hdl.handle.net/1721.1/103014 An Extension of Dematerialization Theory: Incorporation of Technical Performance Increases and the Rebound Effect Magee, Christopher L.; Devezas, Tessaleno C. Dematerialization is the reduction in the quantity of materials needed to produce something useful over time. Dematerialization fundamentally derives from ongoing increases in technical performance but it can be counteracted by demand rebound -increases in usage because of increased value (or decreased cost) that also results from increasing technical performance. A major question then is to what extent technological performance improvement can offset and is offsetting continuously increasing economic consumption. This paper contributes to answering this question by offering some simple quantitative extensions to the theory of dematerialization. An inequality criterion for dematerialization is developed that includes technical performance changes over time and demand rebound effects: the inequality highlights the importance of demand elasticity and the annual technical performance improvement rate. The paper then empirically examines the materials consumption trends as well as cost trends for a large set of materials and a few modern artifacts over the past decades. In all 57 cases examined, the particular combinations of demand elasticity and technical capability rate improvement for each case are consistent with continuation of materialization. Overall, the theory extension and empirical examination indicate that dematerialization and sustainability are significant challenges not easily met by undirected technological change. Tue, 01 Jul 2014 00:00:00 GMT https://hdl.handle.net/1721.1/103014 2014-07-01T00:00:00Z https://hdl.handle.net/1721.1/103013 Endogenous Control of Service Rates in Stochastic and Dynamic Queuing Models of Airport Congestion Jacquillat, Alexandre; Odoni, Amedeo R. Airport congestion mitigation requires reliable delay estimates. This paper presents an integrated model of airport congestion that combines a tactical model of capacity utilization into a strategic queuing model. The model quantifies the relationships between flight schedules, airport capacity and flight delays, while accounting for the way arrival and departure service rates can be controlled over the day to maximize operating efficiency. We show that the model estimates well the average and variability of the delays observed at New York’s airports. Results suggest that delays can be extremely sensitive to even small changes in flight schedules or airport capacity. Tue, 01 Jul 2014 00:00:00 GMT https://hdl.handle.net/1721.1/103013 2014-07-01T00:00:00Z https://hdl.handle.net/1721.1/103012 Capacity pricing schemes to implement open-access rail in Tanzania Pena-Alcaraz, Maite; Perez-Arriaga, Jose Ignacio; Sussman, Joseph M. We analyze alternative capacity pricing schemes (access charges) to implement an open-access railway system in Tanzania. We show that the implementation of variable access charges widely used in the railway industry may result in levels of traffic lower than the traffic operated by an integrated railway company. We propose the use of fixed access charges to avoid this problem and discuss the main advantages and disadvantages to implement them in the context of multiple freight train services in Tanzania. Sun, 01 Jun 2014 00:00:00 GMT https://hdl.handle.net/1721.1/103012 2014-06-01T00:00:00Z https://hdl.handle.net/1721.1/103011 Optimizing Long-Term Service Agreements for gas-fired units in the context of increasing penetration of intermittent generation Leung, Tommy; Sanchez-Gonzalez, Miguel; Rodilla, Pablo; Batlle Lopez, Carlos As power systems increasingly rely on gas-fired power plants (GFPP), and as thermal cycling requirements increase due to larger penetrations of intermittent generation, the long-term service agreements (LTSAs) that define the conditions and costs for GFPP maintenance are exerting more economic influence over a power system’s short-term operations. In a previous paper, the authors proposed a unit commitment formulation that explicitly represents LTSAs and showed that these operations and maintenance (O&M) contracts substantially impact the cost of economic dispatch when GFPPs are forced to intensively cycle. The authors also showed that properly modeling these contracts can substantially alter a power system’s short term optimal scheduling. Traditional LTSAs were designed assuming that (especially) combined cycle gas turbines would operate in a base-loaded regime. In new operating regimes characterized by heavy cycling, GFPPs with traditional LTSAs can incur excessive cycling costs. It may be possible for owners of these GFPPs to renegotiate their existing LTSAs for more flexible conditions that will allow their GFPPs to cycle at lower costs, even if this renegotiation requires the owner to pay an upfront expense. In this paper, we propose a formulation aimed at supporting the process of optimizing LTSAs contracts for a portfolio of GFPPs. Sun, 01 Jun 2014 00:00:00 GMT https://hdl.handle.net/1721.1/103011 2014-06-01T00:00:00Z https://hdl.handle.net/1721.1/103010 ESD Summer Reading Lists 2003–2014 Sussman, Joseph M. Back in 2003, when ESD was a toddler of about 4 1⁄2, we were preparing for our spring semester offsite traditionally held at the end of the academic year in late May or early June. I had the idea of preparing a short list of books with relevance to the ESD mission-the study of complex sociotechnical systems-and presented that idea to the then (and founding) ESD director Prof. Daniel Roos. He agreed it would be worthwhile as an experiment, and so I did create the first ESD Summer Faculty Reading List. A “summer” reading list carries the suggestion of books you can take to “the beach”. So no “text books” were included. The books were treatments of critical contemporary issues that the world faces, important methods and perspectives germane to these issues and the complex sociotechnical systems in general, and relevant history. In retrospect, the beach would likely be too distracting a venue for many of these books! I got some “attaboys” on the 2003 list. A number of my colleagues said it was nice to take a look at my ideas about what books might be interesting reading. So with that positive feedback, I began to do this ESD Faculty Summer Reading List each year. When I did it the second year, I noted that this had now become a “tradition” and with an organization as young as ESD, we needed all the traditions we could get. You can see where it has gone from here. The tradition has continued to the present day, with now twelve years of history for this reading list. In the early days, the commentary on the books was largely my own. As years wore on we would include materials that others-the publisher or book reviewers-had prepared with some supplementary comments from me. And in later years my comments became less and less prevalent and even non-existent. Another thing we did regularly was to include books that had been published during that current academic year by ESD faculty/teaching staff, so this served as a mechanism for highlighting the scholarly work of my ESD colleagues and in 2013, two books published by MIT Press and Penguin Press book were included. In any case, we have these reading lists encompassing books over this twelve-year period and thought it would be helpful to publish it as an ESD working paper to give our colleagues at MIT and outside the Institute access in one document to this eclectic potpourri of books. You may even find something you want to read that you missed the first time around. We hope the reader finds this compendium to be useful and we look forward to any feedback that you may have including suggestions for 2015 and forward. Sun, 01 Jun 2014 00:00:00 GMT https://hdl.handle.net/1721.1/103010 2014-06-01T00:00:00Z https://hdl.handle.net/1721.1/103009 A type-independent approach to supply-chain strategy evaluation Perez-Franco, Roberto Joaquin; Caplice, Chris; Singh, Mahender; Sheffi, Yossi Extant literature lacks established frameworks or methods that can be used to evaluate a supply chain strategy. In this paper we present a type-independent approach to evaluate a business unit's supply chain strategy as a conceptual system. Using as its starting point a conceptualization of the supply chain strategy known as a functional strategy map, the approach calls for an evaluation of the supply chain strategy along several general evaluation criteria: feasibility, support, coverage, compatibility, sufficiency, synergy, and parsimony. For some of these evaluation criteria, we have proposed an evaluation method. Both the proposed criteria and methods were tested and refined through two action research projects. The ability of the approach to identify conflicts in the supply chain strategy provides evidence in support of its evaluative power. As more replications are conducted, our understanding of the capabilities and limitations of both the criteria and the method are bound to improve. At this point, nevertheless, the method and criteria have shown enough promise to warrant further exploration and refinement, and represent a novel contribution to the literature. Sun, 01 Jun 2014 00:00:00 GMT https://hdl.handle.net/1721.1/103009 2014-06-01T00:00:00Z https://hdl.handle.net/1721.1/103008 Expressing a supply-chain strategy as a conceptual system Perez-Franco, Roberto Joaquin; Caplice, Chris; Singh, Mahender; Sheffi, Yossi Extant literature lacks established frameworks or methods that can be used to evaluate a supply chain strategy. In this paper we present a type-independent approach to evaluate a business unit's supply chain strategy as a conceptual system. Using as its starting point a conceptualization of the supply chain strategy known as a functional strategy map, the approach calls for an evaluation of the supply chain strategy along several general evaluation criteria: feasibility, support, coverage, compatibility, sufficiency, synergy, and parsimony. For some of these evaluation criteria, we have proposed an evaluation method. Both the proposed criteria and methods were tested and refined through two action research projects. The ability of the approach to identify conflicts in the supply chain strategy provides evidence in support of its evaluative power. As more replications are conducted, our understanding of the capabilities and limitations of both the criteria and the method are bound to improve. At this point, nevertheless, the method and criteria have shown enough promise to warrant further exploration and refinement, and represent a novel contribution to the literature. Sun, 01 Jun 2014 00:00:00 GMT https://hdl.handle.net/1721.1/103008 2014-06-01T00:00:00Z https://hdl.handle.net/1721.1/103007 Concepts and Mechanics of Evaluating Infrastructure Public-Private Partnerships: A discussion of key practical issues, illustrated through a case example Sakhrani, Vivek; de Neufville, Richard This text presents and illustrates crucially important concepts about how to perform a proper economic evaluation of an infrastructure public-private partnership (PPP) and appreciate the contractual value implications for the partners. The discussion speaks to managers, policy-makers, and all those concerned with the development of infrastructure projects. The discussion pays special attention to the economic issues associated with contracts between public and private sector partners for infrastructure projects. Contracts can be powerful instruments in shaping both overall project value, and the benefits to the contracting parties. The presentation starts with an overview of the concepts central to the evaluation of both general and PPP projects. It then presents the essential elements of the standard spreadsheet analysis of economic value. It illustrates the analysis using a realistic case study of a hypothetical public-private partnership for developing and operating a major international airport. This case provides a useful vehicle for illustrating the important concepts and mechanics of evaluating public-private projects. Thu, 01 May 2014 00:00:00 GMT https://hdl.handle.net/1721.1/103007 2014-05-01T00:00:00Z https://hdl.handle.net/1721.1/103005 Train Timetable Design for Shared Railway Systems using a Linear Programming Approach to Approximate Dynamic Programming Pena-Alcaraz, Maite; Webster, Mort; Ramos, Andres In the last 15 years, the use of rail infrastructure by different train operating companies (shared railway system) has been proposed as a way to improve infrastructure utilization and to increase efficiency in the railway industry. Shared use requires coordination between the infrastructure manager and multiple train operators in a competitive framework, so that regulators must design appropriate capacity pricing and allocation mechanisms. However, the resulting capacity utilization from a given mechanism in the railway industry cannot be known in the absence of operations. Therefore assessment of capacity requires the determination of the train timetable, which eliminates any potential conflicts in bids from the operators. Although there is a broad literature that proposes train timetabling methods for railway systems with single operators, there are few models for shared competitive railway systems. This paper proposes a train timetabling model for shared railway systems that explicitly considers network effects and the existence of multiple operators requesting to operate several types of trains traveling along different routes in the network. The model is formulated and solved both as a mixed integer linear programming (MILP) problem (using a commercial solver) and as a dynamic programming (DP) problem. We solve the DP formulation with a novel algorithm based on a linear programming (LP) approach to approximate dynamic programming (ADP) that can solve much larger problems than are computationally intractable with commercial MILP solvers. The model simulates the optimal decisions by an infrastructure manager for a shared railway system with respect to a given objective function and safety constraints. This model can be used to evaluate alternative capacity pricing and allocation mechanism. We demonstrate the method for one possible capacity pricing and allocation mechanism, and show how the competing demands and the decisions of the infrastructure manager under this mechanism impact the operations on a shared railway system for all stakeholders. Thu, 01 May 2014 00:00:00 GMT https://hdl.handle.net/1721.1/103005 2014-05-01T00:00:00Z https://hdl.handle.net/1721.1/103004 Innovation Dynamics in the Development of Nuclear Energy and Electric Vehicles in France Doufene, Abdelkrim; Siddiqi, Afreen; de Weck, Olivier L. Technological change is shaped by a confluence of processes that are governed by socio-political, economic, and regulatory factors within a region. In this paper we describe the transformation of the electricity generation system in France and the emerging changes in the transportation sector in the country. We trace the impact of national energy security policy in France after the 1973 oil crisis that catalyzed a shift from dependence on fossil fuel to nuclear power, and then examine the continuing impacts of that legacy that are now emerging through development and deployment of electric vehicles in the country. We examine the two cases of nuclear power and electric vehicles in France using processes of innovation, and discuss the interaction of these processes that formed reinforcing loops to advance these technologies in the country and highlight the role of sustained policy in initiating and driving the reinforcing cycles. We also discuss the issue of new emerging linkages between the electric power generation and transportation sectors that were traditionally decoupled due to use of different fuel sources. We expand the notion of path dependence, and discuss how established technologies in one sector can shape future technological trajectory in other sectors. Tue, 01 Apr 2014 00:00:00 GMT https://hdl.handle.net/1721.1/103004 2014-04-01T00:00:00Z https://hdl.handle.net/1721.1/103003 Flexibility, Complexity, and Controllability in Large Scale Systems Broniatowski, David A.; Moses, Joel System structure is a key determinant of system behavior. There is a particularly strong link between a system’s structure and its flexibility – it’s capacity to respond to changes. Often, adding flexibility entails adding complexity. In this paper, we propose measures for a system’s complexity that are complementary to existing flexibility measures. Furthermore, flexibility often comes at the cost of some measure of control over the system’s behavior. We therefore propose a metric for system controllability that is complementary to our flexibility metric. Sat, 01 Mar 2014 00:00:00 GMT https://hdl.handle.net/1721.1/103003 2014-03-01T00:00:00Z https://hdl.handle.net/1721.1/103002 Assessing Future Water Availability in Arid Regions Using Composition and Salience of Decision Criteria Siddiqi, Afreen; Ereiqat, Farah; Diaz Anadon, Laura Water resources development options are usually selected on a least-cost basis. While economic considerations are dominant in choosing projects, there are also a mix of other factors including social demands, political expediency, social equity, and environmental considerations that impact final decisions and development of water supply systems. Understanding local priorities in water resource management decisions can allow for forming expectations of future regional water availability. In this research, we propose that future water availability in arid regions may be assessed by considering key projects that have been identified or planned by regional experts. Using Multi-Criteria Decision Analysis methods as a framework to organize set of decision criteria and their relative salience, the likelihood of selection (and development) of a project can be determined and used to form expectations of future regional water availability. We use this approach in a case study for Jordan, and find that large-scale desalination projects—that have been in the planning books for decades—are now most likely to be pursued and implemented in the country. Finally, we discuss strengths, limitations, and the general applicability of this method for assessing future water availability in other arid regions. Sat, 01 Mar 2014 00:00:00 GMT https://hdl.handle.net/1721.1/103002 2014-03-01T00:00:00Z https://hdl.handle.net/1721.1/103000 The Role of Subproject Task-Specific Attributes in Managing Enterprise-Wide Projects Orhof, Ori; Shenhar, Aaron; Dori, Dov Realizing that different types of projects require different styles of management is becoming part of the mainstream theory and practice in project management. This paper addresses the question of whether the same notion is also applicable to the subproject level, and how. We suggest that a project’s building blocks exhibit unique characteristics with respect to two major dimensions: Challenge (or difficulty) and vitality (or importance). Specifically, we add to the critical path and critical chain project management concepts a critical component—a unit at the sub-project level that is exceptionally risky to a project’s success. We lay out the conceptual framework in which critical component is embedded and demonstrate the theoretical and managerial aspects of contingency at the subproject level by analyzing three case studies. Sat, 01 Mar 2014 00:00:00 GMT https://hdl.handle.net/1721.1/103000 2014-03-01T00:00:00Z https://hdl.handle.net/1721.1/102999 Lesson Study and Lesson Sharing: An Appealing Marriage Hird, Mackenzie D.; Larson, Richard Charles; Okubo, Yuko; Uchino, Kanji Lesson Study and lesson sharing are two educational initiatives that, if merged, have the potential to revolutionize how teachers plan and deliver lessons. Lesson Study is the joint production of lessons by a small team of teachers over the course of a few months. The resulting lesson plan is usually “on paper” and used only locally. Lesson sharing occurs on the Internet, providing contributing teachers with a mechanism for sharing their lessons with others. Typically a single teacher authors these shared lessons. We discuss the advantages and associated implementation barriers of each when viewed as separate activities, and then argue for their joint or merged implementation, describing how each would synergistically support the other. Not only would more vetted lessons be delivered to the Internet, but also the teacher teams participating in lesson creation would develop a much deeper understanding of pedagogy. We offer policy recommendations to support this new educational paradigm: A virtual marriage of Lesson Study and lesson sharing. Sat, 01 Mar 2014 00:00:00 GMT https://hdl.handle.net/1721.1/102999 2014-03-01T00:00:00Z https://hdl.handle.net/1721.1/102998 Engineering Effective Response to Outbreaks of Influenza Finkelstein, Stan Neil; Larson, Richard Charles; Nigmatulina, Karima; Teytelman, Anna Objective. Allocation of vaccines and deployment of non-pharmaceutical interventions (NPIs) are critical to controlling influenza. We examine how these policies can minimize the societal impact. Methods. An engineering systems framing and modeling approach incorporates theories and data on the spread of influenza. Models employed data from the CDC and state governments on cases and vaccine administered during the 2009 H1N1 outbreak, and published literature on how to reduce human-to-human contacts. Results. During the outbreak, barely half of all states received proportional allotments of vaccine in time to protect any citizens, while fewer sought vaccine after the peak. While individuals prone to contract and spread infection drive the progression, diligent hygiene practices and social distancing measures can drive down the number of cases. Conclusions. NPIs are highly effective in reducing the spread of influenza before, but also after vaccine is administered. Policies to allocate vaccine in direct proportion to population should be replaced and larger stocks sent to regions where greater numbers of persons stand to be protected. Sat, 01 Mar 2014 00:00:00 GMT https://hdl.handle.net/1721.1/102998 2014-03-01T00:00:00Z https://hdl.handle.net/1721.1/102994 Rail Infrastructure Manager Problem: Analyzing Capacity Pricing and Allocation in Shared Railway System Pena-Alcaraz, Maite; Webster, Mort D.; Ramos, Andres; Sussman, Joseph M. This paper proposes a train timetabling model for shared railway systems. The model is formulated as a mixed integer linear programming problem and solved both using commercial software and a novel algorithm based on approximate dynamic programming. The results of the train timetabling model can be used to simulate and evaluate the behavior of the infrastructure manager in shared railway systems under different capacity pricing and allocation mechanisms. This would allow regulators and decision makers to identify the implications of these mechanisms for different stakeholders considering the specific characteristics of the system. Sat, 01 Mar 2014 00:00:00 GMT https://hdl.handle.net/1721.1/102994 2014-03-01T00:00:00Z https://hdl.handle.net/1721.1/102992 Hiring College Graduates to Flip Hamburgers: An Endogenous Theory of Professionalization Ghaffarzadegan, Navid; Hue, Yi; Larson, Richard Charles In this paper, we offer an endogenous theory of professionalization and ever-higher degree attainment. We theorize that higher education is a self-driving growth engine. We introduce two endogenous mechanisms that act on the education enterprise, causing the number of educated people to increase dramatically with relatively short-term changes in the job market. Using an illustrative dynamic model based on simple rules of degree attainment and job selection, we argue that these self-driving growth engines are adequate to over-incentivize degree attainment, and can affect the match between supply and demand for college-educated labor. We also show that the mechanisms magnify effects of short-term recessions or technological changes, and create long-term waves of mismatch between workforce and jobs. The implication of the theory is degree inflation, magnified pressures on those with lower degrees, underemployment, and job market mismatch and inefficiency. Sat, 01 Mar 2014 00:00:00 GMT https://hdl.handle.net/1721.1/102992 2014-03-01T00:00:00Z https://hdl.handle.net/1721.1/102991 A Joint Planning, Management and Operations Framework for Airport Infrastructure Jacquillat, Alexandre; Sakhrani, Vivek Many airports around the world are actively considering development or expansion projects. Such projects can spur tremendous benefits but are investment-intensive and span several decades from conception to completion. We formulate the associated dynamic, complex decision-making problems using a broad systems frame. We propose a conceptual framework that links airport infrastructure investments and airport management and operations in a time-expanded, state-contingent problem. To develop this framework we consider the social and policy objectives for well functioning air transportation infrastructure, the decision levers available to stakeholders, the influence of the institutional field and regulatory context on these decisions, and the key performance measures that operationalize system ilities. Our framework integrates literature from investments under uncertainty, airport demand management, and airport operating procedures. Four case examples of airports in Delhi, Charlotte, London and New York illustrate decision-making in the context of our framework. We argue for a more integrated approach to decision-making while evaluating investments in greenfield airports or capacity expansions. Sat, 01 Mar 2014 00:00:00 GMT https://hdl.handle.net/1721.1/102991 2014-03-01T00:00:00Z https://hdl.handle.net/1721.1/102989 Understanding Crude Oil Transport Strategies in North America Carlson, S. Joel; Sussman, Joseph M. On July 6, 2013, an oil-laden unit train derailed and exploded in Lac-Mégantic, Quebec, killing 47 people, shocking many, and leading to significantly increased public scrutiny of crude oil by rail. Simultaneously, there has been intense scrutiny of several proposed pipelines from the oil sands of northern Alberta. Not only is there concern about the potential environmental impacts of the pipelines themselves, such as a potential spill of diluted bitumen (a form of crude oil to be shipped), but also about the consequences of greenhouse gas (GHG) emissions caused by the energy-intensiveness of bitumen production and refining. From the point of view of the railroads, until such impacts are considered through political and regulatory processes in Canada and the US, railroads deciding whether to invest in capacity to transport bitumen are presented with considerable uncertainty. Using both qualitative and quantitative approaches, this paper characterizes some of this uncertainty and discusses its short- and long-term implications for railroads and policy makers. Sat, 01 Mar 2014 00:00:00 GMT https://hdl.handle.net/1721.1/102989 2014-03-01T00:00:00Z https://hdl.handle.net/1721.1/102988 Improving the Systems Engineering Process with Multilevel Analysis of Interactions Eppinger, Steven D.; Joglekar, Nitin R.; Olechowski, Alison L.; Teo, Terence The systems engineering V (SE-V) is an established process model to guide the development of complex engineering projects (INCOSE, 2011). The SE-V process involves decomposition and integration of system elements through a sequence of tasks that produce both a system design and its testing specifications, followed by successive levels of build, integration, and test activities. This paper presents a method to improve SE-V implementation by mapping multilevel data into design structure matrix (DSM) models. DSM is a representation methodology for identifying interactions either between components or tasks associated with a complex engineering project (Eppinger & Browning, 2012). Multilevel refers to SE-V data on complex interactions that are germane either at multiple levels of analysis, e.g. component versus subsystem conducted either within a single phase or across multiple time phases, e.g. early or late in the SE-V process. This method extends conventional DSM representation schema by incorporating multilevel test coverage data as vectors into the off diagonal cells. These vectors provide a richer description of potential interactions between product architecture and SE-V integration test tasks than conventional domain mapping matrices (DMMs). We illustrate this method with data from a complex engineering project in the offshore oil industry. Data analysis identifies potential for unanticipated outcomes based on incomplete coverage of SE-V interactions during integration tests. Additionally, assessment of multilevel features using maximum and minimum function queries isolates all the interfaces that are associated with either early or late revelations of integration risks based on the planned suite of SE-V integration tests. Sat, 01 Mar 2014 00:00:00 GMT https://hdl.handle.net/1721.1/102988 2014-03-01T00:00:00Z https://hdl.handle.net/1721.1/102987 Revisiting the Question: Are Systems of Systems just (traditional) Systems or are they a new class of Systems? Mekdeci, Brian; Shah, Nirav; Ross, Adam Michael; Rhodes, Donna H.; Hastings, Daniel E. This paper revisits a question asked and debated widely over the past decade: are Systems of Systems (SoS) just traditional systems or are they a new class of systems? Many have argued that SoS are a new class of systems, but little research has been available to provide evidence of this. In this paper we share highlights of recent research to show SoS not only have a different structure than systems and thus need to be engineered differently, but also may possess different attributes for beyond first use properties (the “illities”) such as flexibility and adaptability as compared to systems. By examining historical examples and by using a maritime security SoS as a research test bed, this paper shows that the “ility” called survivability had some design strategies that were directly mapped from systems and also allowed new strategies that only made sense for a SoS (e.g. vigilance). The paper also shows that some design strategies have a different implementation and meaning (e.g. margin) at the level of a system compared to SoS level. We conclude the answer to the question “Are SoS’s just systems?” is both yes and no. They are manifestly systems but possess properties not found in traditional systems. This is shown to true of the meta-property of survivability as applied against a directed SoS. Sat, 01 Mar 2014 00:00:00 GMT https://hdl.handle.net/1721.1/102987 2014-03-01T00:00:00Z https://hdl.handle.net/1721.1/102985 Annotated Bibliography of Papers Relevant to High-speed Rail, Regional Economic Development and Related Areas Archila, Andres-Felipe; Sussman, Joseph M. With HSR continuing to be the target of investments around the world, and with even the United States elevating the place of HSR on its public agenda, we have developed this annotated bibliography of references on HSR, regional economic development and related areas. We hope it will be of value to researchers, teachers, students and practitioners. We make no claim of completeness but we can attest that all the references contained herein have been useful to the Regional Transportation Planning and High-speed Rail Research Group. In Section A, we include references on transportation investment and economic development in general. Section B considers the case of HSR and economic development on the local and urban scale while Section C deals with the national, regional and international levels. Section D includes references on economic geography and disparities among regions. In Section E, we include references on HSR and aviation. Section F presents references on transportation project (including HSR projects) financing and value capture mechanisms. Section G deals with HSR organization and reform and Section H discusses HSR integration policy. Finally, Section I discusses international HSR experiences and Section J concludes with references on the Northeast Corridor of the U.S. Each section is subdivided in two categories: 1) papers and 2) books, reports, and theses. Sun, 01 Dec 2013 00:00:00 GMT https://hdl.handle.net/1721.1/102985 2013-12-01T00:00:00Z https://hdl.handle.net/1721.1/102984 Innovative Concept Model Design for Linking Physicians to the System of Patient-Centered Care with Advancing Technologies in the World of Diabetes Hashmi, Sahar; Nightingale, Deborah J. This concept paper applies the concepts of complex sociotechnical engineering systems to the care and management of type 2 diabetes. It also includes an innovative design model that integrates the existing ecosystem of care and management of diabetes. This model could potentially improve quality of care, create transparency of information between patient and physician and decrease the overall cost of care of diabetes. Sun, 01 Dec 2013 00:00:00 GMT https://hdl.handle.net/1721.1/102984 2013-12-01T00:00:00Z https://hdl.handle.net/1721.1/102983 Transport infrastructure evaluation using cost-benefit analysis: improvements to valuing the asset through residual value—a case study Jones, Heather; Domingos, Tiago; Moura, Felipe; Sussman, Joseph M. Residual value (RV) is an important component of Cost Benefit Analysis (CBA), often valued at 20% to 50% of total construction costs. It is often overlooked which can artificially depress the project?s returns. The treatment of RV is inadequate and needs further research. Residual value represents the value of the infrastructure at the end of its project lifetime and the value that the asset generates from then on. We analyze three methods for calculating RV: straight-line depreciation, annuity/perpetuity and component. The straight-line depreciation method is the most commonly used; it is simple and quick to produce and it typically uses a percent of the total construction cost rather than real value. The perpetuity/annuity method ignores the actual value of the asset. It reflects the difference of costs and benefits between economic and useful life (annuity method) or assumes an infinite economic life (perpetuity method). The component method is the most detailed and difficult to calculate method. It gives the actual value of the physical asset at the end of project appraisal by infrastructure component. We assume three scenarios for the future for the component method. We use the case study of the Portuguese High Speed Rail project to calculate and compare each method. As expected, the perpetuity has the highest RV and net present value (NPV), followed by the annuity method and then the component method. The straight-line method produces the lowest values (other than one scenario for the component method). Sensitivity analysis is performed ceteris paribus for the demand, construction cost and discount rate factors. We conclude that RV is important in situations when the benefit-cost ratio is close to 1 and the method selected can have a large impact on the size (and sign) of the NPV. Fri, 01 Aug 2014 00:00:00 GMT https://hdl.handle.net/1721.1/102983 2014-08-01T00:00:00Z https://hdl.handle.net/1721.1/102982 System Design and Architecture of an Online, Adaptive, and Personalized Learning Platform Shaw, Cole; Larson, Richard Charles The authors propose that personalized learning can be brought to traditional and nontraditional learners through a new type of asynchronous learning platform called Guided Learning Pathways (GLP). The GLP platform allows learners to intelligently traverse a vast field of learning resources, emphasizing content only of direct relevance to the learner and presenting it in a way that matches the learner’s pedagogical preference and contextual interests. GLP allows learners to advance towards individual learning goals at their own pace, with learning materials catered to each learner’s interests and motivations. Learning communities would support learners moving through similar topics. This report describes the software system design and architecture required to support Guided Learning Pathways. The authors provide detailed information on eight software applications within GLP, including specific learning benefits and features of each. These applications include content maps, learning nuggets, and nugget recommendation algorithms. A learner scenario helps readers visualize the functionality of the platform. To describe the platform’s software architecture, the authors provide conceptual data models, process flow models, and service group definitions. This report also provides a discussion on the potential social impact of GLP in two areas: higher education institutions and the broader economy. Fri, 01 Nov 2013 00:00:00 GMT https://hdl.handle.net/1721.1/102982 2013-11-01T00:00:00Z https://hdl.handle.net/1721.1/102980 Gas-Electricity Coordination in Competitive Markets under Renewable Energy Uncertainty Duenas, Pablo; Leung, Tommy; Gil, Maria; Reneses, Javier As climate concerns, low natural gas prices, and renewable technologies increase the electric power sector’s dependence on natural gas-fired power plants, operational and investment models for gas and electric power systems will need to incorporate the interdependencies between these two systems to accurately capture the impacts of one on the other. Currently, few hybrid gas-electricity models exist. This paper reviews the state of the art for hybrid gas-electricity models and presents a new model and case study to illustrate a few potential coupling effects between gas and electric power systems. Specifically, the proposed model analyzes the optimal operation of gas-fired power plants in a competitive electricity market taking into consideration gas purchases, gas capacity contracting, and residual demand uncertainty for the generation company due to renewable energy sources. Tue, 01 Oct 2013 00:00:00 GMT https://hdl.handle.net/1721.1/102980 2013-10-01T00:00:00Z https://hdl.handle.net/1721.1/102979 Prospects for grid-connected solar PV in Kenya: A simulated economic and operational feasibility study Rose, Amy Michelle; Stoner, Robert James; Perez-Arriaga, Jose Ignacio This paper analyzes the economic and technical potential for grid-connected solar PV in Kenya. A unit commitment model is used to evaluate the feasibility of grid-connected solar PV under different price and hydrological conditions in the years 2012 and 2017. In the model, Kenya’s extensive reservoir hydro system compensates for daily and seasonal solar intermittency, eliminating the need for investment in battery or other storage capacity. Results show that in the 2012 system the economic value per kW installed of high penetrations of solar PV is greater than the expected revenue under the existing Kenyan feed-in-tariff. This is because solar displaces more expensive fixed and leased fuel oil generation. Evaluation of solar PV under three possible generation mix and demand scenarios in 2017 reveals that the value of solar remains above revenues from the offered feed-in-tariff only if planned investments in low-cost geothermal, imported hydro, and wind power are delayed. The paper focuses on solar investment and no attempt has been made to estimate the theoretical optimal mix. We do not take into account differences in transmission investment associated with different types of generation, which seem likely to favor solar PV in most planning scenarios, nor do we assign monetary value to avoided carbon emissions. The methodology can also be used to estimate the potential for solar and other renewable deployment in many other African countries whose generation capacity is reservoir hydro dominated, or where baseload capacity is provided by costly fossil fuels such as diesel, kerosene, or liquefied natural gas. Sun, 01 Sep 2013 00:00:00 GMT https://hdl.handle.net/1721.1/102979 2013-09-01T00:00:00Z https://hdl.handle.net/1721.1/102978 Congestion Mitigation through Schedule Coordination at JFK: An Integrated Approach Jacquillat, Alexandre; Odoni, Amedeo R. Most flight delays are created by large temporary or long-term imbalances between demand and capacity at the busiest airports. Absent large increases in capacity, airport congestion can only be mitigated through improvements in the utilization of available capacity and the implementation of demand management measures. This paper presents an integrated approach that jointly optimizes the airport’s flight schedule at the strategic level and the utilization of airport capacity at the tactical level, subject to scheduling and capacity constraints. The capacity utilization part involves controlling the runway configuration and the balance of arrival and departure service rates to minimize congestion costs. The schedule optimization reschedules a selected set of flights to reduce the demand-capacity mismatches while minimizing interference with airline competitive scheduling. We develop an original iterative solution algorithm that integrates airport stochastic queue dynamics and a Dynamic Programming model of airport operating procedures into an Integer Programming model of flight rescheduling. The algorithm is shown to converge in reasonable computational times and is thus implementable in practice. Extensive computational results for JFK Airport suggest that very substantial delay reductions can be achieved through limited changes in airline schedules. It is also shown that the proposed integrated approach to airport congestion mitigation performs significantly better than the typical sequential approach where scheduling and operational decisions are made separately. Thu, 01 Aug 2013 00:00:00 GMT https://hdl.handle.net/1721.1/102978 2013-08-01T00:00:00Z https://hdl.handle.net/1721.1/102977 Productivity of Passenger Rail Transportation Services in the Northeast Corridor Archila, Andres-Felipe; Sakamoto, Ryusuke; Fearing, Rebecca Cassler; Sussman, Joseph M. Technological changes, capital investment, organizational reforms, and external factors can impact railway productivity. Using non-parametric single-factor and multifactor productivity (SFP and MFP) Törnqvist trans-log index approaches, we evaluated the performance of high-speed rail (HSR) lines in the U.S. during FY 2002-2012. Intercity rail transportation in the NEC experienced considerable yet highly volatile productivity growth during FY 2002-2012, in the range of ~1-3% per year. Amtrak increased its ability to economically exploit the available capacity, but did not perform equally well on the supply side. The NEC became cumulatively 20% more productive on the demand side but only 3% on the supply side of productivity with respect to 2005 levels. Service changes, technical problems with trains, targeted capital investments, and economic recession and recovery were the main drivers of productivity change. The main train services, the Acela Express and Northeast Regional, were very sensitive to external events, had large economies of scale, and implemented slow adjustment of capacity via rolling stock and infrastructure improvements, which varied depending on the service. In the face of ongoing planning efforts, the NEC could consider the resurgence of demand and recent substantial productivity improvements to launch ambitious plans for HSR. Additional ideas of organization and coordination of rail could reveal hidden opportunities for future HSR development. Fri, 01 Nov 2013 00:00:00 GMT https://hdl.handle.net/1721.1/102977 2013-11-01T00:00:00Z https://hdl.handle.net/1721.1/102976 Uncertainty and Inter-jurisdictional High-speed Rail Planning: Insights from Portugal and the United Kingdom Stein, Naomi; Sussman, Joseph M. Within public policy and academic discourses, high-speed rail (HSR) is presented as a way of achieving “smarter” or more sustainable forms of growth. Realizing this promise requires coordinated policy efforts across levels of government and at different moments along a project’s timeline. The research presented here makes use of a systems perspective to study the barriers to- and opportunities of inter-jurisdictional HSR planning. The paper draws on interview material with officials involved in the Portuguese and United Kingdom HSR planning processes. Uncertainty is found to be of significant relevance to the manner in which national and local or regional governments interact. Those interactions in turn affect the realized physical reality of the HSR network and its integration into existing land use and transport systems. The paper examines two sources of uncertainty—uncertainty of outcomes and the uncertainty of a multi-actor inter-jurisdictional system of control. Case studies are used to explore how existing processes and evaluations mechanisms affect the level to which local knowledge and initiatives are incorporated into iterative HSR system design. The research additionally reveals how initial conditions can be important determinants of HSR success by shaping a system’s ability to adapt to realizations of currently uncertain futures. The paper concludes by offering two approaches to building a HSR implementation process that successfully incorporates HSR-supportive local and regional policies. The approaches combine formal inter-jurisdictional planning commitments with informal coalition building, to together enhance HSR’s ability to achieve its full potential. Fri, 01 Nov 2013 00:00:00 GMT https://hdl.handle.net/1721.1/102976 2013-11-01T00:00:00Z https://hdl.handle.net/1721.1/102975 Airport Congestion Mitigation through Dynamic Control of Runway Configurations and of Arrival and Departure Service Rates under Stochastic Operating Conditions Jacquillat, Alexandre; Odoni, Amedeo R.; Webster, Mort D. The high levels of flight delays require the implementation of airport congestion mitigation tools. In this paper, we optimize the utilization of airport capacity at the tactical level in the face of operational uncertainty. We formulate an original Dynamic Programming model that selects jointly and dynamically runway configurations and the balance of arrival and departure service rates at a busy airport to minimize congestion costs, under stochastic queue dynamics and stochastic operating conditions. The control is exercised as a function of flight schedules, of arrival and departure queue lengths and of weather and wind conditions. We implement the model in a realistic setting at JFK Airport. The exact Dynamic Programming algorithm terminates within reasonable time frames. In addition, we implement an approximate one-step look-ahead algorithm that considerably accelerates the execution of the model and results in close-to-optimal policies. In combination, these solution algorithms enable the on-line implementation of the model using real-time information on flight schedules and meteorological conditions. The application of the model shows that the optimal policy is path-dependent, i.e., it depends on prior decisions and on the stochastic evolution of arrival and departure queues during the day. This underscores the theoretical and practical need for integrating operating stochasticity into the decision-making framework. From comparisons with an alternative model based on deterministic queue dynamics, we estimate the benefit of considering queue stochasticity at 5% to 20%. Finally, comparisons with advanced heuristics aimed to imitate actual operating procedures suggest that the model can yield significant cost savings, estimated at 20% to 30%. Thu, 01 May 2014 00:00:00 GMT https://hdl.handle.net/1721.1/102975 2014-05-01T00:00:00Z https://hdl.handle.net/1721.1/102972 The impact of high-speed rail and low-cost carriers on European air passenger traffic Clewlow, Regina R.; Sussman, Joseph M.; Balakrishnan, Hamsa The expansion of high-speed passenger rail service is often argued as a potentially effective, lower-carbon substitute for intercity air travel. Previous studies on high-speed rail on air travel in Europe and Asia have primarily examined the impact of travel time and price on market share for a specific city pair (or a handful of city pairs). There has been little focus on the extent to which high-speed rail (HSR) has reduced total short-haul air travel demand (versus market share), or on the potential impacts of high-speed rail on system-wide air travel demand. This paper presents an empirical, econometric analysis of air travel demand in Europe, utilizing an expanded data set to explore: 1) the impact of rail travel times, population density, and market characteristics on air tra c; and 2) the impact of high-speed rail and low-cost-carriers on system-wide air traffic. Although improvements in rail travel times have resulted in reductions in short-haul air travel, variations in city and airport characteristics significantly influence the substitution between air and rail. This paper also finds that HSR substitution has resulted in a modest reduction in system-wide air travel demand, whereas the expansion of low-cost carriers has led to a significant increase in total European air traffic. As concerns about the climate impacts of transportation grow, these results have significant implications for future transport and energy policy. Mon, 01 Jul 2013 00:00:00 GMT https://hdl.handle.net/1721.1/102972 2013-07-01T00:00:00Z https://hdl.handle.net/1721.1/102971 ESD Summer Reading Lists 2003–2013 Sussman, Joseph M. Back in 2003, when ESD was a toddler of about 4 1⁄2, we were preparing for our spring semester offsite traditionally held at the end of the academic year in late May or early June. I had the idea of preparing a short list of books with relevance to the ESD mission-the study of complex sociotechnical systems-and presented that idea to the then (and founding) ESD director Prof. Daniel Roos. He agreed it would be worthwhile as an experiment, and so I did create the first ESD Summer Faculty Reading List. A “summer” reading list carries the suggestion of books you can take to “the beach”. So no “text books” were included. The books were treatments of critical contemporary issues that the world faces, important methods and perspectives germane to these issues and the complex sociotechnical systems in general, and relevant history. In retrospect, the beach would likely be too distracting a venue for many of these books! I got some “attaboys” on the 2003 list. A number of my colleagues said it was nice to take a look at my ideas about what books might be interesting reading. So with that positive feedback, I began to do this ESD Faculty Summer Reading List each year. When I did it the second year, I noted that this had now become a “tradition” and with an organization as young as ESD, we needed all the traditions we could get. You can see where it has gone from here. The tradition has continued to the present day, with now eleven years of history for this reading list. In the early days, the commentary on the books was largely my own. As years wore on we would include materials that others-the publisher or book reviewers-had prepared with some supplementary comments from me. And in later years my comments became less and less prevalent and even non-existent. Another thing we did regularly was to include books that had been published during that current academic year by ESD faculty, so this served as a mechanism for highlighting the scholarly work of my ESD colleagues and in 2012, the four books in the MIT Press Engineering Systems book series were all included. In any case, we have these reading lists encompassing books over this eleven-year period and thought it would be helpful to publish it as an ESD working paper to give our colleagues at MIT and outside the Institute access in one document to this eclectic potpourri of books. You may even find something you want to read that you missed the first time around. We hope the reader finds this compendium to be useful and we look forward to any feedback that you may have including suggestions for 2014 and forward. Sat, 01 Jun 2013 00:00:00 GMT https://hdl.handle.net/1721.1/102971 2013-06-01T00:00:00Z https://hdl.handle.net/1721.1/102970 NEC FUTURE Preliminary Alternatives Report: Public Comment Sussman, Joseph M.; Archila, Andres F.; Carlson, S. Joel; Pena-Alcaraz, Maite; Soshi, Kawakami; Westrom, Ryan J.; Stein, Naomi The United States Department of Transportation's Federal Railroad Administration (FRA) is currently in the early stages of a planning process to define a 30-year passenger rail investment plan for the Northeast Corridor (NEC), between Boston and Washington, D.C. In the Spring of 2013, NEC FUTURE (the name of the planning process), released a Preliminary Alternatives Report, containing 15 possible alternatives for passenger rail infrastructure investment. This working paper contains a memo from the Regional Transportation Planning and High Speed Rail Research Group at the Massachusetts Institute of Technology (MIT) responding to the Preliminary Alternatives Report, as well as following up on the group's previous public comments to NEC FUTURE (ESD-WP-2012-27 NEC FUTURE Tier I Scoping Process: Public Comment). The memo focuses on the group's reactions in three areas: “goals and objectives, and evaluation of the alternatives,” “planning under uncertainty and flexible alternatives,” and “institutional assumptions.” These comments also build on the knowledge gained from report prepared for and funded by the Institute for Transportation Policy Studies (ITPS) in Tokyo, Japan, entitled Transportation in the Northeast Corridor of the U.S.: A Multimodal and Intermodal Conceptual Framework. Sat, 01 Jun 2013 00:00:00 GMT https://hdl.handle.net/1721.1/102970 2013-06-01T00:00:00Z https://hdl.handle.net/1721.1/102968 Carbon Efficiency of Humanitarian Supply Chains: Evidence from French Red Cross operations Oberhofer, Peter; Blanco, Edgar; Craig, Anthony J. Natural catastrophes are often amplified by man-made impact on the environment. Sustainability is identified as a major gap in humanitarian logistics research literature. Although humanitarian supply chains are designed for speed and sustainability is of minor concern, environmentally-friendly behavior (e.g. through reduction of transportation emissions and avoidance of non-degradable materials) should be a long-term concern as it may ultimately affect more vulnerable regions. The purpose of this paper is to illustrate how green house gas emissions can be measured using the supply chain of common relief items in humanitarian logistics. We analyze the CO2 emissions of selected supply chains by performing Life Cycle Assessments based on data provided by the French Red Cross. We calculate the CO2 emissions of the items from ‘cradle to grave’ including production, transportation, warehousing and disposal. Using these calculations, we show that transporting relief items causes the majority of emissions; however, transportation modes may not always be changed as the main purpose of humanitarian supply chains is speed. Nevertheless, strategic and efficient pre-positioning of main items will translate into less transportation and thus reducing the environmental impact. The study also shows that initiatives for “greening” item production and disposal can improve the overall carbon efficiency of humanitarian supply chains. Sat, 01 Jun 2013 00:00:00 GMT https://hdl.handle.net/1721.1/102968 2013-06-01T00:00:00Z https://hdl.handle.net/1721.1/102967 House of Project Complexity – Understanding Complexity in Large Infrastructure Projects Lessard, Donald Ray; Sakhrani, Vivek; Miller, Roger This paper describes our conceptualization of complexity in Large Infrastructure Projects (LIPs). Since complexity itself is an emergent concept that is hard to pin down, we focus on the relationship between various project features and, particularly, properties associated with complexity such as difficulty, outcome variability and non-linearity, and (non) governability. We propose a combined structural and process-based theoretical framework for understanding contributors to complexity in this particular substantive context – the “House of Project Complexity” (HoPC). The HoPC addresses the impact of inherent technical and institutional project features, the process of project architecting, the structural relationship between various project features and these “designed” constructs, and the emergence of risks and life-cycle properties (‘ilities’). The HoPC is first applied to two trial samples and then to the main data set of detailed case studies of infrastructure projects prepared for the IMEC study. We believe that the “House of Project Complexity” can be generally extended to other substantive contexts that exhibit similar properties as Large Infrastructure Projects (LIPs), in the extractive industries, large manufacturing projects, or other industrial megaprojects. Wed, 01 May 2013 00:00:00 GMT https://hdl.handle.net/1721.1/102967 2013-05-01T00:00:00Z https://hdl.handle.net/1721.1/102965 Making Infrastructure Procurement Processes more Flexible under Uncertainty Sakhrani, Vivek; Jordan, Luke; de Neufville, Richard A third to a half of development projects undergo restructuring due to changes in project objectives, scope or other unanticipated changes, therefore requiring schedule extensions, budget additions and rework. Current procurement processes discourage managers from responding strategically by anticipating and preparing for such changes in advance through better information search and design concept evaluation. This paper suggests three principles for making the front-end phases of procurement more flexible - understanding uncertainty, studying system-wide impacts, and phasing designs. A case study analysis of urban water system design in Kabul demonstrates the conceptual and analytical application of these principles. Wed, 01 May 2013 00:00:00 GMT https://hdl.handle.net/1721.1/102965 2013-05-01T00:00:00Z https://hdl.handle.net/1721.1/102964 The Coming Hangover: Magnified Effects of Sequestration on Research Enterprises Ghaffarzadegan, Navid; Larson, Richard Charles; Hawley, Joshua As of March 1, 2013 the US government is taking an $85 billion budget cut. Also referred as the “sequestration”, this automatic spending cut policy might continue for several upcoming years and potentially affect many industries, including the research enterprise. The cut is expected to reflect in the budget of federal agencies that support research activities, such as the National Institutes of Health (NIH) and the National Science Foundation (NSF). For a wide range of structural reasons, discussed in this commentary, the impacts of the budget cut on research enterprises can be magnified. Fri, 01 Mar 2013 00:00:00 GMT https://hdl.handle.net/1721.1/102964 2013-03-01T00:00:00Z https://hdl.handle.net/1721.1/102963 Too Many Ph.D. Graduates or Too Few Academic Job Openings: The Basic Reproductive Number R[subscript 0] in Academia Larson, Richard Charles; Ghaffarzadegan, Navid; Xue, Yi The academic job market has become increasingly competitive for Ph.D. graduates. In this Note we ask the basic question of “Are we producing more Ph.D.’s than needed?” We take a systems approach and offer a “birth rate” perspective: professors graduate Ph.D.’s who later become professors themselves, an analog to how a population grows. We show that the reproduction rate in academia is very high. For example, in engineering, a professor in the U.S. graduates 7.8 new Ph.D.’s during his/her whole career on average, and only one of these graduates can replace the professor’s position. This implies that in a steady state, only 12.8% of Ph.D. graduates can attain academic positions in the U.S. The key insight is that the system in many places is saturated, far beyond capacity to absorb new Ph.D.’s in academia at the rates that they are being produced. Based on the analysis, we discuss policy implications. Fri, 01 Mar 2013 00:00:00 GMT https://hdl.handle.net/1721.1/102963 2013-03-01T00:00:00Z https://hdl.handle.net/1721.1/102961 Carbon Efficient Logistics: A Case study in Modal Shift Oberhofer, Peter; Blanco, Edgar E. Corporate sustainability is becoming increasingly important in the development of business strategies. Consequently, transport and logistics operations come under particular scrutiny due to their substantial impact on the environment. The aim of this paper is to illustrate two successful examples where logistics performance is optimized in tandem with a reduction in carbon emission. The selected case study provides documented examples, detailing how GHG reductions can be achieved while improving business efficiency. The following two initiatives of an US company of the paper and packaging producing sector will be presented: Initiative I: The company works closely with their customers to promote rail transport. Goods are directly sent from production plants which operate their own railway connection to the customer that is also located along the railway. In 2011, the promotion of rail transport on 4 US routes saved 62–72% CO[subscript 2] emission (1,500-2,300 tons of CO[subscript 2]) compared to trucking. These savings are equivalent to taking 300-450 cars off the road every year. Initiative II: The company uses space-efficient pallets in selected railcars and thereby increases the number of shipped goods. Besides optimizing the spatial utilization of the cars, CO[subscript 2] can be saved by transporting more goods on the same railcar. 190 tons of CO[subscript 2] were saved by using space-efficient pallets in 930 railcars in 2011. This equals the CO[subscript 2] emission caused by 21,637 gallons of gasoline consumed by road vehicles. The case study calculations illustrate, step-by-step, how the reductions were estimated, and provide a detailed “road map” for future participants to implement and properly estimate the GHG reductions. Additionally, we also aim to present ‘Carbon Footprinting’ as a useful method of environmental monitoring and reporting and discuss different methodological approaches. Fri, 01 Feb 2013 00:00:00 GMT https://hdl.handle.net/1721.1/102961 2013-02-01T00:00:00Z https://hdl.handle.net/1721.1/102960 Heterogeneous Unit Clustering for Efficient Operational Flexibility Modeling for Strategic Models Palmintier, Bryan S.; Webster, Mort D. The increasing penetration of wind generation has led to significant improvements in unit commitment models. However, long-term capacity planning methods have not been similarly modified to address the challenges of a system with a large fraction of generation from variable sources. Designing future capacity mixes with adequate flexibility requires an embedded approximation of the unit commitment problem to capture operating constraints. Here we propose a method, based on clustering units, for a simplified unit commitment model with dramatic improvements in solution time that enable its use as a submodel within a capacity expansion framework. Heterogeneous clustering speeds computation by aggregating similar but non-identical units thereby replacing large numbers of binary commitment variables with fewer integers that still capture individual unit decisions and constraints. We demonstrate the trade-off between accuracy and run-time for different levels of aggregation. A numeric example using an ERCOT-based 205-unit system illustrates that careful aggregation introduces errors of 0.05-0.9% across several metrics while providing several orders of magnitude faster solution times (400x) compared to traditional binary formulations and further aggregation increases errors slightly (~2x) with further speedup (2000x). We also compare other simplifications that can provide an additional order of magnitude speed-up for some problems. Tue, 01 Jan 2013 00:00:00 GMT https://hdl.handle.net/1721.1/102960 2013-01-01T00:00:00Z https://hdl.handle.net/1721.1/102959 Optimal Selection of Sample Weeks for Approximating the Net Load in Generation Planning Problems De Sisternes Jimenez, Fernando; Webster, Mort D. The increasing presence of variable energy resources (VER) in power systems –most notably wind and solar power– demands tools capable of evaluating the flexibility needs to compensate for the resulting variability in the system. Capacity expansion models are needed that embed unit commitment decisions and constraints to account for the interaction between hourly variability and realistic operating constraints. However, the dimensionality of this problem grows proportionally with the time horizon of the load profile used to characterize the system, requiring massive amounts of computing resources. One possible solution to overcome this computational problem is to select a small number of representative weeks, but there is no consistent criterion to select these weeks, or to assess the validity of the approximation. This paper proposes a methodology to optimally select a given number of representative weeks that jointly characterize demand and VER output for capacity planning models aimed at evaluating flexibility needs. It also presents different measures to assess the error between the approximation and the complete time series. Finally, it demonstrates that the proposed methodology yields a valid approximation for unit commitment constraints embedded in long-term planning models. Tue, 01 Jan 2013 00:00:00 GMT https://hdl.handle.net/1721.1/102959 2013-01-01T00:00:00Z https://hdl.handle.net/1721.1/102958 Residential satisfaction close to highways: The impact of accessibility, nuisances and highway adjustment projects Hamersma, Marije; Tillema, Taede; Sussman, Joseph M.; Arts, Jos In this paper we focus on gaining insight into the residential satisfaction of households near highways, based on survey data collected among 1,225 respondents in the Netherlands living within 1,000 meters from a highway. Ordinal regression was used to study the impact of highway externalities on residential satisfaction. Moreover, we gained first insights into the reactions of people on highway adjustment projects, by studying people’s expectations towards residential satisfaction as a consequence of the project with use of a multinomial logistic regression analysis. On average, 85 percent of respondents reported being satisfied with living near a highway. Regarding explanatory characteristics, subjective evaluations of air and noise nuisance and of accessibility are of comparable importance and seem to outperform objective exposure calculations or distance from the highway or access lane in explaining residential satisfaction. Moreover highway interest is directly reflected in a higher satisfaction. However, other factors such as neighborhood design, traffic safety and social cohesion are important as well. People react differently to highway adjustment plans, negative expectations being highly driven by current negative feelings towards nuisance, and positive expectations by personal interest in accessibility and a positive attitude towards cars. An important implication could be the notion that exposure is not the same as perceived nuisance, which may give reason to be cautious when making transportation planning decisions based solely on calculations. In addition, the finding that other (neighborhood) factors are also very important in explaining residential satisfaction is interesting when thinking about compensating for the negative effects of a highway in the neighborhood. Also, the results regarding reactions to an announced highway adjustment project might be used to better adjust the planning process to the characteristics of the residents in the area. Further research is necessary to deepen the results, for example through the addition of other road project locations, interviews and longitudinal data. Tue, 01 Jan 2013 00:00:00 GMT https://hdl.handle.net/1721.1/102958 2013-01-01T00:00:00Z https://hdl.handle.net/1721.1/102957 A Systems Thinking Approach to Leading Indicators in the Petrochemical Industry Leveson, Nancy G. There are always warning signs before a major accident, but these signs may only be noticeable or interpretable as a leading indicator in hindsight. Before an accident, such “weak signals” are often perceived only as noise. To ask people to “be mindful of weak signals” is asking them to do something that is impossible. There is always a lot of noise and always a lot of signals that do not presage an accident. The problem then becomes how to distinguish the important signals from all the noise. Defining effective leading indicators is a way to accomplish this goal by providing specific clues that people need to look for. Asking people to “look for anything that might be an important sign” is usually asking them to do the impossible. Almost all of the past effort to identify leading indicators has involved finding a set of generally applicable metrics or signals that presage an accident. Examples of such identified leading indicators are quality and backlog of maintenance, inspection, and corrective action; minor incidents such as leaks or spills, equipment failure rates, and so on. There is commonly a belief—or perhaps, hope—that a small number of such “leading indicators” can identify an increase in risk of an accident. While some general indicators may be useful, large amounts of effort over decades has not provided much progress. The lack of progress may be a sign that such general, industry-wide indicators do not exist or will not be particularly effective in identifying increasing risk. An alternative is to identify leading indicators that are specific to the system being monitored. This paper proposes an approach to identifying and monitoring system-specific leading indicators and provides some guidance in designing a risk management structure to use such indicators effectively. The approach is based on the STAMP model of accident causation and tools that have been designed to build on that model. STAMP extends current accident causality to include more complex causes than simply component failures and chains of failure events. It incorporates basic principles of systems thinking and is based on systems theory rather than traditional reliability theory. The next section briefly describes STAMP and STPA, the latter being a new hazard analysis technique based on STAMP. Then the proposal for a new approach to generating and managing leading indicators is outlined. Tue, 01 Jan 2013 00:00:00 GMT https://hdl.handle.net/1721.1/102957 2013-01-01T00:00:00Z https://hdl.handle.net/1721.1/102940 NEC FUTURE Tier I Scoping Process: Public Comment Sussman, Joseph M.; Archila, Andres F.; Carlson, S. Joel; Pena-Alcaraz, Maite; Stein, Naomi; Westrom, Ryan J. Utilizing its special expertise, the Regional Transportation Planning and High Speed Rail Research Group at the Massachusetts Institute of Technology (MIT) sought to provide input via public comment to the NEC FUTURE Tier I scoping process. Earlier in 2012, we completed a comprehensive look at the complexities and challenges associated with mobility in the NEC. This submittal is based on a report prepared for and funded by the Institute for Transportation Policy Studies (ITPS) in Tokyo, Japan, entitled Transportation in the Northeast Corridor of the U.S.: A Multimodal and Intermodal Conceptual Framework. We applied novel combinations of system analysis methods to seek new insights for planning in this corridor. With the lessons learned from this account, we seek to provide input to the NEC FUTURE scoping process, and enrich the NEC FUTURE Tier I EIS study. We recognize that the Purpose and Need and a comprehensive and carefully articulated range of alternatives are of utmost importance for the EIS process, and we are focusing our comments in these two areas. With our lessons learned, we hope to offer insights useful in formulating and refining the project’s Purpose and Need, and as well in defining the alternatives to be considered. Mon, 01 Oct 2012 00:00:00 GMT https://hdl.handle.net/1721.1/102940 2012-10-01T00:00:00Z https://hdl.handle.net/1721.1/102939 A Supply Chain View of Product Carbon Footprints: Results from the Banana Supply Chain Craig, Anthony J.; Blanco, Edgar E.; Sheffi, Yossi Interest in the use of Life Cycle Assessment (LCA) to measure the carbon footprint of products has increased in recent years. While issues have been raised regarding the use of LCA to measure carbon footprints, the difficulties of doing so in the context of a modern supply chain have received less attention. In this paper we present a case study of the carbon footprint of bananas done in partnership with a leading importer of bananas and a U.S. retail grocery chain. Issues related to data quality and access represent a significant hurdle in measuring the carbon footprint across a supply chain, and we analyze our results in the context of ownership of the supply chain through the use of the GHG Protocol’s concept of emission scopes. Sharing information between supply chain partners has been promoted as one method of resolving data issues, but raises important issues related to supply chain variability. Through an analysis of the impact of transportation we show how the structure of a supply chain introduces significant variability in the carbon footprint required to serve different customers. Wed, 01 Aug 2012 00:00:00 GMT https://hdl.handle.net/1721.1/102939 2012-08-01T00:00:00Z https://hdl.handle.net/1721.1/102938 Estimating the CO[subscript 2] Intensity of Intermodal Freight Transportation Craig, Anthony J.; Blanco, Edgar E.; Sheffi, Yossi Greenhouse gas emissions from transportation represent a significant and growing amount of total global emissions, with road freight among the fastest growing areas. Modal shift from road to rail is one of a number of proposed strategies for reducing emissions, and intermodal transport offers shippers an attractive alternative to truckload service. Unfortunately little data is available to shippers to calculate the potential savings of a modal shift. In this paper we analyze a data set of more than 400,000 intermodal shipments to calculate the CO[subscript 2] intensity of intermodal transportation as a distinct mode. We compare our results to a publicly available intermodal emissions calculator and apply the market area concept to explain the variance between individual shipments. The results provide useful guidance for shippers to estimate the potential reductions through modal shift and identify areas for intermodal operators to improve service. Wed, 01 Aug 2012 00:00:00 GMT https://hdl.handle.net/1721.1/102938 2012-08-01T00:00:00Z https://hdl.handle.net/1721.1/102937 Analysis of High-Speed Rail Implementation Alternatives in the Northeast Corridor: the Role of Institutional and Technological Flexibility Pena-Alcaraz, Maite; Carlson, S. Joel; Archila, Andres F.; Stein, Naomi; Sussman, Joseph M. In this paper, an engineering systems framework using the CLIOS Process, scenario analysis, and flexibility analysis is used to study the implementation of a high-speed rail corridor in the Northeast Corridor of the United States. Given the tremendous uncertainty that characterizes high-speed rail projects, the implementation of the alternatives proposed, which are very similar to other commonly accepted ways to implement high-speed rail in the corridor, are analyzed under different scenarios. The results motivate incorporation of flexibility into the alternatives to allow decision makers to adapt as situations evolve. While designing-in this flexibility has a cost, it may facilitate the implementation of the alternatives by enabling adaptation to uncertain outcomes, thereby improving performance. Sun, 01 Jul 2012 00:00:00 GMT https://hdl.handle.net/1721.1/102937 2012-07-01T00:00:00Z https://hdl.handle.net/1721.1/102936 Discontinuous Regions: High-Speed Rail and the Limits of Traditional Governance Stein, Naomi; Sussman, Joseph M. Globalization and the interconnectivity of the economy have magnified the role of regions, restructuring social and economic relationships into networks that span increasing distances. At the same time, greater attention is due to localized urban quality, as non-vehicular modes and compact forms of development become critical in an environmentally conscious world. Within this context, increasing interest and adoption of high-speed rail (HSR)—a mode that addresses multiple scales—is unsurprising. HSR technology is used both to respond to existing trends of increased interconnectivity between urban centers and to enhance economic connections within regions and mega-regions. HSR has the unique ability to enable long-distance commuting across discontinuous regions that are far enough apart so as not to be adequately integrated by auto travel. This new geography of daily experiences has important potential implications for governance and relations among cities. Using Portugal as a case study, this paper examines the relationship between HSR development and new models of spatial organization and governance. Based on interviews with national and local officials, we discuss ways in which HSR planning is changing attitudes towards regional identity and urban governance, including: the integration of national entities into local planning processes, the potential for new models of commuting, and the role of HSR as an exogenous catalyst for regional cooperation. The case study reveals how HSR can serve as a catalyst for governments to rethink regional identity, intergovernmental relationships, and competitive positioning. The prospect of HSR implementation raises the profile of potential intraregional complementarity and highlights the importance of inter-governmental relationships. Sun, 01 Jul 2012 00:00:00 GMT https://hdl.handle.net/1721.1/102936 2012-07-01T00:00:00Z https://hdl.handle.net/1721.1/102935 Knowledge Diversity in the Emerging Global Bio-Nano Sector Maine, Elicia; Bliemel, Martin; Murira, Armstrong; Utterback, James M. As scientists are able to understand and manipulate ever smaller scales of matter, research in the fields of biotechnology and nanotechnology has converged to enable such radical innovations as lab-on-a-chip devices, targeted drug delivery, and other forms of minimally invasive therapy and diagnostics. This paper provides a descriptive overview of the emerging bio-nano sector, identifying what types of firms are entering, from what knowledge base, where they are located, and their strategic choices in terms of technological diversity and R&D strategy. The firms engaged in bio-nano research and development span the range from start-up firm to multinational pharmaceutical, biotech, chemical, and electronics firms: two thirds of bio-nano firms are relatively young and relatively small. The United States dominates this sector, with more than half of all bio-nano firms located in the USA. Even within this sector which epitomizes the convergence of technology, there is a broad range of technological diversity, with the most diverse firms overall coming from a base in electronics, the most diverse start-up firms coming from a base in nanomaterials, and the most narrowly focused firms coming from a biotechnology/pharmaceutical base. We find that hybridization has been the dominant knowledge diversity strategy, with 93% of the bio-nano firms with nano-patents holding multiclass patents. Sun, 01 Apr 2012 00:00:00 GMT https://hdl.handle.net/1721.1/102935 2012-04-01T00:00:00Z https://hdl.handle.net/1721.1/102934 ESD Summer Reading Lists 2003–2012 Sussman, Joseph M. Back in 2003, when ESD was a toddler of about 4 1⁄2, we were preparing for our spring semester offsite traditionally held at the end of the academic year in late May or early June. I had the idea of preparing a short list of books with relevance to the ESD mission-the study of complex sociotechnical systems-and presented that idea to the then (and founding) ESD director Prof. Daniel Roos. He agreed it would be worthwhile as an experiment, and so I did create the first ESD Summer Faculty Reading List. A “summer” reading list carries the suggestion of books you can take to “the beach”. So no “text books” were included. The books were treatments of critical contemporary issues that the world faces, important methods and perspectives germane to these issues and the complex sociotechnical systems in general, and relevant history. In retrospect, the beach would likely be too distracting a venue for many of these books! I got some “attaboys” on the 2003 list. A number of my colleagues said it was nice to take a look at my ideas about what books might be interesting reading. So with that positive feedback, I began to do this ESD Faculty Summer Reading List each year. When I did it the second year, I noted that this had now become a “tradition” and with an organization as young as ESD, we needed all the traditions we could get. You can see where it has gone from here. The tradition has continued to the present day, with now ten years of history for this reading list. In the early days, the commentary on the books was largely my own. As years wore on we would include materials that others-the publisher or book reviewers-had prepared with some supplementary comments from me. And in later years my comments became less and less prevalent and even non-existent. Another thing we did regularly was to include books that had been published during that current academic year by ESD faculty, so this served as a mechanism for highlighting the scholarly work of my ESD colleagues and in 2012, the four books in the MIT Press Engineering Systems book series were all included. In any case, we have these reading lists encompassing books over this ten-year period and thought it would be helpful to publish it as an ESD working paper to give our colleagues at MIT and outside the Institute access in one document to this eclectic potpourri of books. You may even find something you want to read that you missed the first time around. We hope the reader finds this compendium to be useful and we look forward to any feedback that you may have including suggestions for 2013 and forward. Fri, 01 Jun 2012 00:00:00 GMT https://hdl.handle.net/1721.1/102934 2012-06-01T00:00:00Z https://hdl.handle.net/1721.1/102933 Designing Sorting Facilities in Reverse Logistics Systems Ponce-Cueto, Eva; Blanco, Edgar E.; Duque Ciceri, Natalia The main aim of this paper is to propose a multi-waste mix integer lineal programming model for locating sorting facilities in a three-level (local, regional, and central) reverse logistic network. The objective of the model is to decide the location of the storage and sorting facilities across the network. The model was applied in end of life battery recycling network in Spain. As capacity is constrained, the optimal solution moves towards a combination of regional and local facilities for storage and a central facility for sorting. Fri, 01 Jun 2012 00:00:00 GMT https://hdl.handle.net/1721.1/102933 2012-06-01T00:00:00Z https://hdl.handle.net/1721.1/102932 Streamlined Life Cycle Assessment of Carbon Footprint of a Tourist Food Menu Using Probabilistic Underspecification Methodology Lee, Yin Jin; Blanco, Edgar E.; Yang, Xu We proposed a methodology based on life cycle assessment streamlining techniques to estimate the carbon footprint (CF) of a meal. The methodology was applied to estimate the meal CF of twenty-four people on a 4-days Galapagos Island tour using over three hundred existing Life Cycle Analysis (LCA) results in the food industry. In spite of the abundance of food LCA studies, there were very little food CF studies on food produced in South America or Ecuador. By combining established and novel life cycle assessment streamlining techniques, we demonstrated how to (a) calculate the uncertainty associated with the use of surrogate CF data, (b) carry out a preliminary carbon footprint calculation using surrogate data to identify a subset of components that contributes the greatest CFs to the product, which we called the set of interest (SOI) and, (c) greatly reduce the uncertainty in the CF results using only exact CFs for the SOI in addition to the surrogate CFs of the other food items. In general, this methodology can systematically cut down the time and resources that are needed to collect all the emission data in the production of food in a meal, but to focus on only a small handful of food items that impact the total CF, provided that the surrogate CF database is large enough to include the true CF. Fri, 01 Jun 2012 00:00:00 GMT https://hdl.handle.net/1721.1/102932 2012-06-01T00:00:00Z https://hdl.handle.net/1721.1/102931 Multichannel Distribution Strategies in Latin America Blanco, Edgar E.; Garza, Jaime The process of designing and selecting distribution channels is challenging and it demands an in-depth understanding of the market. Leading firms competing in Latin America are exploring creative ways to effectively reach and efficiently serve each segment of the market. This paper characterizes the key drivers that shape the design and selection of sales and distribution channels. Based on a series of workshops and in-depth analyses from 14 enterprises and 35 distinct distribution schemes we identify key factors and propose a framework that characterize drivers currently used by Latin American companies to design distribution channel strategies. Fri, 01 Jun 2012 00:00:00 GMT https://hdl.handle.net/1721.1/102931 2012-06-01T00:00:00Z https://hdl.handle.net/1721.1/102930 Carbon Footprint of the Galapagos Islands – Quantifying the Environmental Impact of Tourist Activities Cordova-Vallejo, Ximena M.; Blanco, Edgar E.; Yang, Xu; Ponce-Cueto, Eva The main goal of this paper is to quantify the green house gas emissions (also referred to as carbon footprint) of the Galapagos Islands. The analysis includes emissions from energy generation and of related economic activities of the tourism industry, including international travel to the islands. We have also included the green house gas emission generated by the transportation of fuel, food, supplies and water from Ecuador mainland to Galapagos Islands across multiple modes. We estimated a total carbon footprint of 532,373 tones of CO2-eq, of which 68.82% corresponds to international air travel, 17.86% corresponds to fuel consumption for energy generation and 6.01% due to transportation of food from mainland to the islands. These emissions were allocated between residents and tourists to outline strategies for a sustainable tourism management in the islands. Fri, 01 Jun 2012 00:00:00 GMT https://hdl.handle.net/1721.1/102930 2012-06-01T00:00:00Z https://hdl.handle.net/1721.1/102929 Integrating Engineering Systems Research and Undergraduate Education Through A Term-Length Case Study Dunn, Travis P.; Stein, Naomi; Sussman, Joseph M.; Uniman, David The MIT-Portugal Program (MPP) was launched in 2007 with the dual objectives of conducting innovative research and establishing leading academic degree programs through international collaboration across a range of technical disciplines. Among the first attempts to integrate the research and teaching objectives of the MPP was the Spring 2009 offering of Engineering System Design, a required course for third- and fourth-year undergraduates in MIT’s Department of Civil and Environmental Engineering. The course employed a semester-long case study, drawing heavily on active MPP transportation and engineering systems research for teaching and assignment content. On the research side, MIT has been engaged with partner universities and agencies in Portugal on a variety of topics related to high-speed rail (HSR). These varied efforts demand a unifying engineering systems framework to ensure that the research delivered provides maximal value both individually and as part of a broader program. The integrating engineering systems framework chosen (Complex, Large-Scale, Interconnected, Open, Socio-technical, or CLIOS Process) was taught in Engineering System Design and applied using an active research program as the case study context. After presenting the MPP and HSR research contexts, this paper summarizes the methodology used to implement the CLIOS Process in a classroom setting through an evolving, term-length group project that involved teaching and supervision by faculty and researchers. Next, the paper discusses the challenges of teaching engineering systems concepts to undergraduates, incorporating active research into a classroom setting, and managing large project groups. Finally, the paper summarizes the lessons learned from the course as well as prospects for future applications of engineering systems research in the classroom. It is hoped that those interested in designing undergraduate courses in engineering systems will benefit from the course’s lessons learned, both positive and negative, as summarized here. Thu, 01 Mar 2012 00:00:00 GMT https://hdl.handle.net/1721.1/102929 2012-03-01T00:00:00Z https://hdl.handle.net/1721.1/102928 Complex Socio-technical Problems for Engineers: Pedagogical Motivation and Experience at the Undergraduate Level Siddiqi, Afreen; Clewlow, Regina; Sussman, Joseph M. Engineering courses, focused on complex, large-scale, sociotechnical systems, at the undergraduate level, have been rare. Traditionally, most students develop a deep technical understanding in a specific engineering discipline, but get little opportunity to analyze engineered complex systems, where both technical and social issues need to be well understood for devising long lasting solutions. The development of analytical skills for studying interdisciplinary problems has so far been largely limited at the graduate-level. In this paper we describe the motivation, design, and learning outcomes of an introductory course on Engineering Systems that has been developed and offered to primarily first and second year engineering students at the Massachusetts Institute of Technology. The course has been centered around the theme of critical contemporary issues (CCIs) including energy, mobility, sustainability etc. The aim of the course is to expose undergraduates to quantitative tools that are available for rigorously and methodically analyzing some of our most complex contemporary engineering challenges. The course consists of introductory lectures on system dynamics, networks and uncertainty, along with semester-long team-based projects. The projects focus on different topics related to CCIs and the students work in small teams on a project of their interest throughout the term. For the first pilot offering of the class (in Spring semester 2011), the students gave an average rating of 5.9/7.0 regarding how likely they were to recommend this class to others (with 7 being absolutely certain). There was also evidence (however based on limited and anecdotal data) of continued student interest (outside of class) in engaging with the complex socio-technical problems they worked on during the term. Thu, 01 Mar 2012 00:00:00 GMT https://hdl.handle.net/1721.1/102928 2012-03-01T00:00:00Z https://hdl.handle.net/1721.1/102927 Investigating Relationships and Semantic Sets amongst System Lifecycle Properties (Ilities) de Weck, Olivier L.; Ross, Adam Michael; Rhodes, Donna H. The ilities are properties of engineering systems that often manifest and determine value after a system is put into initial use (e.g. resilience, interoperability, flexibility). Rather than being primary functional requirements, these properties concern wider system impacts with respect to time and stakeholders. Over the past decade there has been increasing attention to ilities in industry, government and academia. Our research suggests that investigating ilities in sets may be more meaningful than study of single ilities in isolation. Some ilities are closely related and do in fact form semantic sets. Here, we use two methods to investigate over twenty ilities in terms of their prevalence and their interrelationships. We look for trends related to ilities of interest in relation to system type and an understanding of their collective use. First, we conducted a prevalence analysis of 22 ilities using both the internet as well as the Compendex/Inspec database as a source. We found over 1,275,000 scientific articles published between 1884 and 2010 and over 1.9 billion hits on the internet, exposing a clear prevalence-based ranking of ilities. Two questions we seek to address are: why and how are the ilities related to one another, and what can we do with this information. Initial steps to answer the first question include a 2-tupel-correlation matrix analysis that exposes the strongest relationships amongst ilities based on concurrent usage. Moreover, we conducted some preliminary experiments that indicate that a hierarchy of ilities with a few major groupings may be most useful. The overall objective for this research is to develop a formalframework and prescriptive guidance for effectively incorporating sets of ilities intothe design of complex engineering systems. Thu, 01 Mar 2012 00:00:00 GMT https://hdl.handle.net/1721.1/102927 2012-03-01T00:00:00Z https://hdl.handle.net/1721.1/102926 Strategic Engineering Gaming for Improved Design and Interoperation of Infrastructure Systems Grogan, Paul T.; de Weck, Olivier L. Large physical networks of interrelated infrastructure components support modern societies as a collaborative system with significant technical and social complexity. Design and evolution of infrastructure systems seeks to reduce wasted resources and maximize lifecycle value. Interdependencies between constituent systems call for an integrative approach to improve interoperation but many existing techniques rely on centralized development and emphasize technical aspects of design. This paper presents a simulation gaming approach to collaborative infrastructure system design leveraging the technical strengths of simulation models and the social strengths of multi-player engagement in a game execution. In a strategic engineering game, models representing each constituent infrastructure system share a common graph-theoretic modeling framework and are integrated using the HLA-Evolved standard for interoperable federated simulations. A prototype game instantiation based on a space-based resource economy supporting future space exploration is discussed with the objective of identifying how factors of game play influence insights to collaborative system design. Future work seeks to develop, execute, and evaluate the prototype game to further research the use of simulation games in supporting collaborative system design. Thu, 01 Mar 2012 00:00:00 GMT https://hdl.handle.net/1721.1/102926 2012-03-01T00:00:00Z https://hdl.handle.net/1721.1/102925 A New Framework to Assess Regional and Urban Impacts of Transport Infrastructure: The Case of High-Speed Rail in Portugal Chen, Guineng; Shen, Yu; Martinez, Luis Miguel; de Abreu e Silva, Joao This paper presents a comprehensive framework for modeling the impacts of large-scale transport infrastructure which have the potential to fundamentally alter the spatial interaction properties of regions, producing significant socio-demographic and economic modifications. This model is being developed as part of a broader research project to assess the impacts of the development of a high-speed rail (HSR) network in Portugal and to evaluate the best infrastructure and service configurations of the system. The framework will be applied to study a future HSR line between Lisbon and Oporto, exploring the concept of megalopolis formation for the corridor. The expected impacts of HSR include rearrangements of the socio-economic structure of the region it serves, redefinition of the nature of the economic linkages to neighboring regions and other external regions, and changes to the urban forms of the various urban centers which will experience significant accessibility upgrades. The framework calls for an agent-based formulation, with decision-making agents at various spatial scales and decision making levels interacting both in space and across levels, producing effects on upper and lower levels of spatial resolution and decision making. The model will include three main types of agents, which are linked to different scales of decision-making and spatial resolution, e.g. municipal, regional, and national. This paper presents the framework of the model, characterizes the interactions among the various levels of decision-making and assessment, and describes the methodological formulation of all the sub-models proposed for this comprehensive simulation tool. Thu, 01 Mar 2012 00:00:00 GMT https://hdl.handle.net/1721.1/102925 2012-03-01T00:00:00Z https://hdl.handle.net/1721.1/102924 Controlling Change Within Complex Systems Through Pliability Mekdeci, Brian; Ross, Adam Michael; Rhodes, Donna H.; Hastings, Daniel E. As systems become larger, more complex, and operate for longer periods of time, some change within the system often becomes inevitable. Particularly in systems of systems, with diverse stakeholders, evolutionary development and managerial independence, it is not unusual for constituent systems to change in form or the way they operate. Changeability, the ability of a system to change, is often considered to be a desirable attribute that allows systems to be robust and to adapt in response to changes in context. However, involuntary changes, such as those that occur as a result of a disturbance, are more often problematic than favorable. In some ways, the survivability of a system depends on its ability to prevent, mitigate and recover from unintentional changes within the system brought about by disturbances. For certain large systems of systems, where there are complex interactions and a diverse set of stakeholders, even voluntary changes may be frowned upon, since it may be an expensive and time consuming process to approve changes. This paper discusses pliability, a new “-ility” that places constraints on the changes a system is allowed to make. Pliability is the ability of a system to change, without “breaking” or violating an architecture that the system architects intended and validated. Like changeability, pliability increases robustness by allowing systems to voluntarily change in response to changing contexts, and increases survivability by increasing the likelihood that unintentional changes are still within the set of allowable instances. It also distinguishes allowable changes from those that would require validation and approval from decision makers, making it easier to actually implement those changes in large, complex systems. Thu, 01 Mar 2012 00:00:00 GMT https://hdl.handle.net/1721.1/102924 2012-03-01T00:00:00Z https://hdl.handle.net/1721.1/102923 Analogies Between Complex Systems and Phases of Matter Moses, Joel; Broniatowski, David A. The behavior of a complex system in a changing environment is strongly affected by the system's architecture. We present an analogy between the major phases of matter (solid, liquid, gas) and three major generic architectures of complex systems: tree structures, layered structures and grid networks. This analogy is realized using a graph-based formalism, with nodes and edges in a given configuration. Solid materials are akin to tree structures, especially when we consider that most solids actually have cracks. Solids with cracks between their components can be modeled by nodes (representing each component) and their interconnection, leading to a tree structured hierarchy. Gases made up of molecules can be modeled by nodes (the molecules) with local interconnections representing nearby molecules in space, thus forming a grid network. Liquids can form layers as in a mixture of oil and water. We represent this by connections that are densely horizontal within layers as well as sparsely vertical between layers. A key issue for complex systems is the ease by which they may be changed, which we call the system’s flexibility. Our definition of flexibility indicates that tree structures, like solids, are relatively inflexible and that grid networks, like gases, are extremely flexible, possibly leading to loss of control and chaotic behavior. Like liquids, layered systems are intermediate in flexibility and controllability. Solids, even with cracks, are relatively difficult to modify, whereas gases change internal form so quickly that they can only be constrained; not controlled. Liquids are intermediate in their ability to change form internally. Just as heating solids can lead to liquids, and heating liquids can result in gases, we shall present transformations in the interconnection structure of systems, analogous to heating, that change tree structures into layered ones and layered structures into networks. Thu, 01 Mar 2012 00:00:00 GMT https://hdl.handle.net/1721.1/102923 2012-03-01T00:00:00Z https://hdl.handle.net/1721.1/102922 Megacities and High Speed Rail systems: which comes first? Pagliara, Francesca; de Abreu e Silva, Joao; Sussman, Joseph M.; Stein, Naomi A megacity is usually defined as a metropolitan area with a total population in excess of 10 million people. The number of megacities is increasing worldwide. In most agglomerations and megacities, urban planning and public infrastructure can guide the urban development in order to achieve a proper sustainable structure only partially. The extension of cities is in most cases in advance of urban development work and the provision of public facilities (Kotter, 2004). In Europe, apart from London and Paris, megacities are rarer. However, due to the general high density of population in Europe and the short distance between medium and large cities there is the possibility of High Speed Rail (HSR) enables the emergence of groups of cities that will be linked together and thus reap the economic benefits associated with megacities, namely economies of scale, economies of agglomeration and bigger labour markets. In this contribution the authors argue that in some cases, specific facilities can foster the formation of megacities; in fact, this is the case of HSR systems. Specifically, High-Speed trains can be used to solve two different accessibility problems. In the first case, where a point-to-point link is dominant, each train is a potential substitute for an air connection between two cities, i.e. it connects cities (or rather CBDs) at long distance with a direct train connection (Blum et al., 1997).The HSR links between Paris and Lyon, Paris and London and, Tokyo and Osaka, could be seen as examples of this first type of train connection. In the second case, where a HSR network is dominant, the rail system links together many cities and CBDs and, hence, creates a new type of region with a high intra-regional accessibility sharing a common labour market and a common market for household and business services. In this case the HSR binds together cities in a band, where each pair of cities is at a time distance of between 20 minutes and 1 hour, allowing daily commuting. In the U.S., HSR projects are very recent and they will have the role of connecting already formed megacities. An example is the state of California, which is planning an 800-mile HSR service connecting Los Angeles and San Francisco into a two and a half hour trip. On the other hand, Europe, together with Asia, is the leader in HSR systems; in fact the development of HSR has been one of the central features of recent European Union transport infrastructure policy. The proposals for a European HSR network emerged in a report of the 1990 Community of European Railways and this was essentially adopted as the base for what became the European Community’s proposed Trans-European Network for HSR (Vickerman, 1997). In this paper the case studies of Portugal, where the HSR is a work in progress and of Italy, in which some lines have already been built, will be described in detail from the viewpoint of the various kinds of development described above. Thu, 01 Mar 2012 00:00:00 GMT https://hdl.handle.net/1721.1/102922 2012-03-01T00:00:00Z https://hdl.handle.net/1721.1/102921 The Earth as an Engineering System: Addressing Sustainability through Science, Technology and Policy Selin, Noelle Eckley; Friedman, Carey L. We combine insights from the two emerging fields of engineering systems and sustainability science to develop an analytical approach for understanding and managing coupled natural and human systems. The Earth system is characterized with reference to the attributes of engineering systems (real-world existence, artificiality, dynamic properties, hybrid state, and some human control). We argue that human influences have become so overwhelming that it is impossible to understand global Earth systems without taking into account both technical and social dimensions. Aspects of sustainability systems that fulfill functional types of engineering systems are enumerated with reference to five processes (transporting, transforming, storing, exchanging and controlling) and operands (living organisms, matter, information, energy and money). Building on methods from sustainability science, we introduce the concept of Spatial-Temporal-Functional (STF) analysis for addressing sustainability problems in an engineering systems context. We illustrate this framework with reference to the case of global transport of hazardous chemicals. Our analysis suggests that efforts to address cross-scale problems should focus on enhancing mechanisms for transforming and exchanging in addition to controlling. Thu, 01 Mar 2012 00:00:00 GMT https://hdl.handle.net/1721.1/102921 2012-03-01T00:00:00Z https://hdl.handle.net/1721.1/102920 The Historical Roots of the Field of Engineering Systems: Results from an In-class Assignment Magee, Christopher L.; Saari, Rebecca K.; Heaps-Nelson, G. Thomas; Zoepf, Stephen M.; Sussman, Joseph M. The field of Engineering Systems (ES) is quite young but there are intellectual roots that go far back in time. At least that is the working hypothesis in an integrative capstone assignment given in the first doctoral subject for incoming ES PhD students at MIT. The assignment has been given for four years (2008-2011) and involves pairs of students researching the intellectual connections between a specific historical root and a specific modern ES method. This paper describes the faculty and student perspectives on the assignment, including the perceived learning outcomes, and insights gained into the roots of Engineering Systems. Some overall observations include: Interconnections among almost all selected topics (whether labeled roots or modern methods) are apparent. Each topic has an extensive time period of unfolding which gives rise to overlap and complex interactions among the topics; Herbert Simon’s work appears most pivotal in the roots of Engineering Systems. Jay Forrester, John von Neumann, Norbert Weiner and Joseph Schumpeter are also identified along with others as having a significant impact; The faculty always learn something about the field from what the students find even when topics are repeated; and, The assignment is a valuable – but not perfect – vehicle for learning about Engineering Systems and for launching budding researchers’ efforts in the field. Thu, 01 Mar 2012 00:00:00 GMT https://hdl.handle.net/1721.1/102920 2012-03-01T00:00:00Z https://hdl.handle.net/1721.1/102919 Uncertainty, Flexibility, Valuation & Design: How 21st Century Information & Knowledge Can Improve 21st Century Urban Development Geltner, David M.; de Neufville, Richard The 21st century presents humankind with perhaps its greatest challenge since our species almost went extinct some 70,000 years ago in Africa. A big part of meeting that challenge lies in how the urbanization of three billion additional people (equal to the entire world population in 1960) will be accomplished between now and mid-century, on top of necessary renewal and renovation of the earth‘s existing cities. China alone will urbanize 300 million more people between now and 2030. (That is equal to the entire population of the U.S., the world‘s third most populous country, and just 20 years!) This is development on a scale and pace that is an order of magnitude greater than the past century, in a world resource and climate environment that is near the breaking point, in a context of greater technological, financial, and economic uncertainty than ever before. To meet this challenge will require that we use the best tools in our kit, including ones that have become available to us only in this new knowledge and information-based century. Technology got us here, and technology will be key to getting us through. In this paper we will review and synthesize two important methodological developments in our profession that can help infrastructure and real estate physical development (i.e., urban development) to be accomplished more effectively and efficiently in a world of uncertainty. The first methodological development is the honing of real options theory and methodology for practical application to identify and evaluate sources of flexibility in the design and operation of capital projects. The second development is the marriage of digital data compilation of property transactions records with the honing of econometric analysis methodology to allow the practical quantification of real estate and infrastructure asset price dynamics. We argue that this latter development provides the key input to the former development, enabling a much more complete and rigorous treatment of design and evaluation problems for urban development. We also argue that an engineering systems approach to option modeling is likely to find better traction in actual professional practice than the economic theoretical models that have dominated the academic literature. We provide a concrete example by applying the suggested approach to the Songdo New City development in Korea. The result can be better informed design and valuation, more efficient urban development laced with greater flexibility to avoid the worst down-side outcomes and to take advantage of the best up-side opportunities, saving vital resources of capital, land, raw materials, and energy. Finally, we argue that a global, thought-leadership institution such as the RICS can and should play a leadership role in supporting and promulgating the new information bases and interdisciplinary educational formations (property, land, construction) that must underpin the successful dissemination of such 21st century tools of analysis. Sun, 01 Jan 2012 00:00:00 GMT https://hdl.handle.net/1721.1/102919 2012-01-01T00:00:00Z https://hdl.handle.net/1721.1/102918 Comparative Analysis of Cybersecurity Metrics to Develop New Hypotheses Madnick, Stuart E.; Choucri, Nazli; Li, Xitong; Ferwerda, Jeremy Few Internet security organizations provide comprehensive, detailed, and reliable quantitative metrics, especially in the international perspective across multiple countries, multiple years, and multiple categories. As common refrain to justify this situation, organizations ask why they should spend valuable time and resources collecting and standardizing data. This report aims to provide an encouraging answer to this question by demonstrating the value that even limited metrics can provide in a comparative perspective. We present some findings generated through the use of a research tool, the Explorations in Cyber Internet Relations (ECIR) Data Dashboard. In essence, this dashboard consists of a simple graphing and analysis tool, coupled with a database consisting of data from disparate national-level cyber data sources provided by governments, Computer Emergency Response Teams (CERTs), and international organizations. Users of the dashboard can select relevant security variables, compare various countries, and scale information as needed. In this paper, using this tool, we present an example of observations concerning the fight against cybercrime, along with several hypotheses attempting to explain the findings. We believe that these preliminary results suggest valuable ways in which such data could be used and we hope this research will help provide the incentives for organizations to increase the quality and quantity of standardized quantitative data available. Sun, 01 Jan 2012 00:00:00 GMT https://hdl.handle.net/1721.1/102918 2012-01-01T00:00:00Z https://hdl.handle.net/1721.1/102917 SPARQL Query Mediation for Data Integration Zheng, Xiaoqing; Li, Xitong; Madnick, Stuart E. The Semantic Web provides a set of promising technologies to make sophisticated data integration much easier, because data on the semantic Web is allowed to be connected by links and complex queries can be executed against the dataset of those linked data. Although the Semantic Web techniques offer RDF/OWL to support schematic mappings between diverse data sources, large-scale data integration is still severely hampered by various types of data-level semantic heterogeneity among the data sources. In the paper, we show that SPARQL queries that are intended to execute over multiple heterogeneous data sources can be mediated automatically. Sun, 01 Jan 2012 00:00:00 GMT https://hdl.handle.net/1721.1/102917 2012-01-01T00:00:00Z https://hdl.handle.net/1721.1/102916 Exploring Terms and Taxonomies Relating to the Cyber International Relations Research Field: or are "Cyberspace" and "Cyber Space" the same? Camina, Steven; Madnick, Stuart E.; Choucri, Nazli; Woon, Wei Lee This project has at least two facets to it: (1) advancing the algorithms in the sub-field of bibliometrics often referred to as "text mining" whereby hundreds of thousands of documents (such as journal articles) are scanned and relationships amongst words and phrases are established and (2) applying these tools in support of the Explorations in Cyber International Relations (ECIR) research effort. In international relations, it is important that all the parties understand each other. Although dictionaries, glossaries, and other sources tell you what words/phrases are supposed to mean (somewhat complicated by the fact that they often contradict each other), they do not tell you how people are actually using them. As an example, when we started, we assumed that "cyberspace" and "cyber space" were essentially the same word with just a minor variation in punctuation (i.e., the space, or lack thereof, between "cyber" and "space") and that the choice of the punctuation was a rather random occurrence. With that assumption in mind, we would expect that the taxonomies that would be constructed by our algorithms using "cyberspace" and "cyber space" as seed terms would be basically the same. As it turned out, they were quite different, both in overall shape and groupings within the taxonomy. Since the overall field of cyber international relations is so new, understanding the field and how people think about (as evidenced by their actual usage of terminology, and how usage changes over time) is an important goal as part of the overall ECIR project. Sun, 01 Jan 2012 00:00:00 GMT https://hdl.handle.net/1721.1/102916 2012-01-01T00:00:00Z https://hdl.handle.net/1721.1/102914 Epistemology in Engineering Systems Frey, Daniel The engineering systems division at MIT has adopted an official vision statement -- “ESD will be a leader in understanding, modeling, predicting and affecting the structure and behavior of technologically enabled complex systems.” To fulfill this vision, I think it is worthwhile for ESD faculty to reflect on epistemology and its relationship to engineering systems. Epistemology is the branch of philosophy concerned with the nature of knowledge, justification, evidence, and related notions. By reflecting upon epistemology, we may clarify in our own minds how we come to know something about engineering systems and thereby improve our research methods. In this white paper, I pose five questions related to epistemology and engineering systems. I also discuss possible answers, but my goal was primarily to spark discussion rather than solidify a position. Mon, 01 Dec 2003 00:00:00 GMT https://hdl.handle.net/1721.1/102914 2003-12-01T00:00:00Z https://hdl.handle.net/1721.1/102912 ITS: What We Know Now that We Wish We Knew Then: A Retrospective on the ITS 1992 Strategic Plan Sussman, Joseph M. From September 1991 until June 1992, a core writing team, which included the author, worked on what was the first Intelligent Transportation Systems (ITS) strategic plan in the United States. This plan was entitled, "A Strategic Plan for IVHS in the United States." It served to define the ITS program at a national scale in a way that has been characterized as seminal. The plan, by most accounts, served as the blueprint for the early development of ITS in the U.S. and as the basis for the subsequent plans produced by ITS America, the federal government, various states, and a number of private-sector organizations. This paper explores numerous aspects of ITS retrospectively, contrasting views from 11 years ago, when the Strategic Plan was produced, with the current reality. Areas discussed include Advanced Traveler Information Systems (ATIS), Advanced Transportation Management Systems (ATMS), reliability, getting the ITS program off the ground in the early 90s, strategic use of information, automated network management, electronic toll collection (ETC), congestion pricing, architecture, commercial vehicle operations (CVO), Advanced Public Transportation Systems (APTS), and regions. The paper closes by comparing ITS with the Interstate, and finally by discussing the upcoming reauthorization of the Transportation Efficiency Act for the 21st Century (TEA-21) and what has been learned through this retrospective about ITS-related issues on that reauthorization. Mon, 01 Sep 2003 00:00:00 GMT https://hdl.handle.net/1721.1/102912 2003-09-01T00:00:00Z https://hdl.handle.net/1721.1/102911 Lean Transformation in the U.S. Aerospace Industry: Appreciating Interdependent Social and Technical Systems Cutcher-Gershenfeld, Joel Lean practices and principles build on a half-century of successive initiatives aimed at transforming social and technical systems in organizations. While they are seen as central to the revitalization of the U.S. aerospace industry, there is great variation in the degree to which lean initiatives emphasize just technical/manufacturing systems versus additional social and enterprise dimensions. Based on a national random sample survey of 362 U.S. aerospace facilities, this paper examines factors that account for the incidence of lean practices and the impact on outcomes relevant to key stakeholders. While structural factors such as industry sector, facility size and others have limited explanatory power, two process factors—organizational learning and the value placed on intellectual capital —do account for the increased presence of lean practices. In examining employment outcomes, facilities higher just on the technical/manufacturing aspects of lean have a significant and negative impact on job growth, while facilities higher around the social systems associated with lean have significant and positive employment growth. This finding is consistent with the views of critics of the more narrow technical, manufacturing-oriented approaches to lean as a threat to employment and it validate proponents of a broader value-creating approach to lean as a way of growing the enterprise. Enterprise dimensions of lean (including both social and technical aspects of lean) have a positive impact on productivity. Examining outcomes relevant to multiple stakeholders and various factor inputs produces a more complete understanding of the limitations and potential for lean transformation in the aerospace industry. Fri, 01 Aug 2003 00:00:00 GMT https://hdl.handle.net/1721.1/102911 2003-08-01T00:00:00Z https://hdl.handle.net/1721.1/102910 A Proposal to Improve the Health Care Systems for the Urban Poor in the Squatter Settlements of the Developing Countries Larson, Richard Charles; Varol, Nebibe Rapid urbanization and large scale population movements from rural to urban areas have resulted in unprecedented health crises in the developing countries. In addition to communicable diseases, respiratory infections and malnutrition, psycho-social stresses due to marginalization and exclusion from social activities and employment prospects are also prevalent. Considering the rate of urban growth rate and the rapid increase in the percentage of the poor living in urban areas, the debilitating effects of health crises and urban poverty are going to exacerbate if no precautions are taken. In this respect, it is a critical point in time to come up with effective health care strategies for the urban poor. This document provides an insight into the reasons behind the current health problems of the urban poor and the determinants of health in developing countries, and proposes use of operations research to come up with handling strategies for the major subdivisions of the health problem in the developing world. Tue, 01 Jul 2003 00:00:00 GMT https://hdl.handle.net/1721.1/102910 2003-07-01T00:00:00Z https://hdl.handle.net/1721.1/102909 Role of Technology in Manufacturing Competitiveness Eagar, Thomas W.; Musso, Christopher A manufacturing revolution has emerged in the past 50 years that is as significant as the industrial revolution of the 19th century. From 1950 to 2000, the average productivity growth in manufacturing in the United States was 2.8% per year, and this figure has been accelerating for the past two decades as manufacturing productivity growth has exceeded the average of other sectors by more than one percent per year (please see table below). Stated more simply, a US manufacturing worker can produce four times as much per hour today as compared with fifty years ago. This gain has resulted from competitive pressures, the advent of new technologies, and a series of product and process innovations. It has also resulted in a much higher standard of living for Americans, as products become more useful and more affordable. In order to utilize this new manufacturing capacity, U.S. firms (and others) have expanded their marketing abroad, creating rapid increase in global trade. The perception of a crisis in American manufacturing is the result of one of the most difficult realities of large gains in productivity: additional capacity almost always exceeds increased consumption. This results in an inevitable shift of labor. Industries become more productive as they mature, and competitive pressures increase. These two factors require companies to decrease their workforce and often result in movement of commodity industries overseas. The end result is a loss of jobs in the United States. Displaced workers must shift to new occupations, requiring new skills and abilities. History has shown that this shift can be either detrimental or beneficial to workers; the most important determinant of benefit is the presence of innovative new industries, which, create high value for their markets. The sustainability of growth in the U.S. manufacturing sector is based on the ability of America to continue to innovate. Innovation is the key to a vibrant U.S. manufacturing base and continued generation of new jobs. Tue, 01 Jul 2003 00:00:00 GMT https://hdl.handle.net/1721.1/102909 2003-07-01T00:00:00Z https://hdl.handle.net/1721.1/102908 How Useful is Quantitative Risk Assessment? Apostolakis, George This article discusses the use of Quantitative Risk Assessment (QRA) in decision-making regarding the safety of complex technological systems. The insights gained by QRA are compared with those from traditional safety methods and it is argued that the two approaches complement each other. It is argued that peer review is an essential part of the QRA process. The importance of risk-informed rather than risk-based decision-making is emphasized. Engineering insights derived from QRAs are always used in combination with traditional safety requirements and it is in this context that they should be reviewed and critiqued. Examples from applications in nuclear power, space systems, and an incinerator of chemical agents are given to demonstrate the practical benefits of QRA. Finally, several common criticisms raised against QRA are addressed. Tue, 01 Jul 2003 00:00:00 GMT https://hdl.handle.net/1721.1/102908 2003-07-01T00:00:00Z https://hdl.handle.net/1721.1/102907 Needs and Possibilities for Engineering Education: One Industrial/Academic Perspective Magee, Christopher L. This paper reports a personal assessment of the readiness of new B.S. level engineering graduates to practice engineering immediately upon graduation. This assessment when reinforced by significant prior work motivates a systemic analysis of the U.S. Engineering Education System. The analysis is framed to address the implementation potential of ideas for how educators might efficiently teach undergraduate engineers “that engineering is more than differential equations”. The concepts which seem best from this analysis are combinations of aggressive intern opportunities combined with courses (starting in the freshman year) that emphasize the creative engineering process. These activities may be containable in the 4 year program but the analysis also suggests that extension of engineering education to 3 or more years beyond the B.S. would improve the possibility of reaching key educational goals including teaching adequate math and science fundamentals as well as engineering knowledge, process and creativity. Such radical change will be difficult and slow to occur (if at all) in this complex system. Moreover, this system is understandingly resistant to change because of significant perceptions of outstanding achievement. The driving force for change that may be strong enough to overcome these barriers is prospective students’ falling perceptions of engineering education as a preferred option. Sun, 01 Jun 2003 00:00:00 GMT https://hdl.handle.net/1721.1/102907 2003-06-01T00:00:00Z https://hdl.handle.net/1721.1/102906 Metrics Pilot Project for Military Avionics Sustainment: Experimental Design and Implementation Plan Bozdogan, Kirkor; Brandt, Benjamin M.; Sussman, Joseph M. This working paper outlines the design of an experiment, employing a pilot project, for identifying and validating new metrics for managing the US Air Force military avionics sustainment system. The paper also presents a plan for implementing the pilot project. The experimental design allows for the quantitifation of the effects of the new metrics, while controlling for the effects of other factors impacting the observed outcomes. Underlying the pilot project, and the proposed experimental design, are three main hypotheses derived from earlier research: (a) currently used metrics foster local optimization rather than system-wide optimization; (b) they do not allow measures of progress towards the achievement of system-wide goals and objectives, and, hence, do not allow visibility into the impact of depot maintenance on the warfighter; and (c) they are driving the “wrong behavior,” causing suboptimal decisions governing maintenance and repair priorities and practices and, as a result, undermining the efficiency and effectiveness of the sustainment system, despite the fact that the Air Force sustainment system has a dedicated and highly skilled workforce supporting the warfighter. Sun, 01 Jun 2003 00:00:00 GMT https://hdl.handle.net/1721.1/102906 2003-06-01T00:00:00Z https://hdl.handle.net/1721.1/102905 Applying STAMP in Accident Analysis Leveson, Nancy G.; Daouk, Mirna; Dulac, Nicolas; Marais, Karen Accident models play a critical role in accident investigation and analysis. Most traditional models are based on an underlying chain of events. These models, however, have serious limitations when used for complex, socio-technical systems. Previously, Leveson proposed a new accident model (STAMP) based on system theory where the basic concept is not an event but a constraint. This paper shows how STAMP can be applied to accident analysis using three different views or models of the accident process and proposes a notation for describing this process. Sun, 01 Jun 2003 00:00:00 GMT https://hdl.handle.net/1721.1/102905 2003-06-01T00:00:00Z https://hdl.handle.net/1721.1/102904 Stopping Pandemic Flu: Government and Community Interventions in a Multi-Community Model Nigmatulina, Karima R.; Larson, Richard Charles Focusing on mitigation strategies for global pandemic influenza, we use elementary mathematical models to evaluate the implementation and timing of intervention strategies such as travel restrictions, vaccination, social distancing and improved hygiene. A spreadsheet model of infection spread between several linked heterogeneous communities is based on analytical calculations and Monte Carlo simulations. Since human behavior will likely change during the course of a pandemic, thereby altering the dynamics of the disease, we incorporate a feedback parameter into our model to reflect altered behavior. Our results indicate that while a flu pandemic could be devastating; there are coping methods that when implemented quickly and correctly can significantly mitigate the severity of a global outbreak. Sat, 01 Dec 2007 00:00:00 GMT https://hdl.handle.net/1721.1/102904 2007-12-01T00:00:00Z https://hdl.handle.net/1721.1/102903 Measuring Systems Engineering Success: Insights from Baseball Blackburn, Craig; Valerdi, Ricardo Optimizing the efficiency of socio-technical systems and determining accurate measurements of performance is a critical issue in many systems engineering enterprises. In our analysis we explore some of the recurring themes of Michael Lewis’s study of baseball, depicted in the best selling book Moneyball, and make the connection to corresponding Systems Engineering principles of interest. The paper will focus on the Systems Engineering roadmap inspired by Lewis’ study for developing and refining a meaningful set of metrics for organizational transformation. The following steps are highlighted to convey this transformation with the assistance of metrics: identify and understand value in the enterprise and your organization; consider an integrated system focus in your organization; use cost analysis methods to implement a strategy for executing the transformation; and manage risk throughout operations and improve the process continuously. Thu, 01 Nov 2007 00:00:00 GMT https://hdl.handle.net/1721.1/102903 2007-11-01T00:00:00Z https://hdl.handle.net/1721.1/102902 Ranking the Risks from Multiple Hazards in a Small Community Li, Hua; Apostolakis, George; Gifun, Joseph; VanSchalkwyk, William; Leite, Susan; Barber, David M. Natural hazards, human-induced accidents, and malicious acts have caused great losses and disruptions to society. After September 11, 2001, critical infrastructure protection has become a national focus in the United States and is likely to remain one for the foreseeable future. Damage to our infrastructures and assets could be mitigated through pre-disaster planning and actions. We have developed a systematic methodology to assess and rank the risks from these multiple hazards in a community of 20,000 people. It is an interdisciplinary study that includes probabilistic risk assessment, decision analysis, and expert judgment. Scenarios are constructed to show how the initiating events evolve into undesirable consequences. A value tree, based on multi-attribute utility theory, is used to capture the decision maker’s preferences about the impacts on the infrastructures and other assets. The risks from random failures are ranked according to their Expected Performance Index, which is the product of frequency, probability, and consequence of a scenario. Risks from malicious acts are ranked according to their Performance Index as the frequency of attack is not available. A deliberative process is used to capture the factors that could not be addressed in the analysis and to scrutinize the results. This methodology provides a framework for the development of a risk-informed decision strategy. Although this study uses the Massachusetts Institute of Technology campus as a test-bed, it is a general methodology that could be used by other similar communities and municipalities. Thu, 01 Nov 2007 00:00:00 GMT https://hdl.handle.net/1721.1/102902 2007-11-01T00:00:00Z https://hdl.handle.net/1721.1/102901 Decision Support and Systems Interoperability in Global Business Management Datta, Shoumen Palit Austin; Lyu, JrJung; Chen, Ping-Shun Globalization of business and volatility of financial markets has catapulted ‘cycle-time’ as a key indicator of operational efficiency in business processes. Systems automation holds the promise to augment the ability of business and healthcare networks to rapidly adapt to changes or respond, with minimal human intervention, under ideal conditions. Currently, system of systems (SOS) or organization of networks contribute minimally in making decisions because collaboration remains elusive due the challenges of complexity. Convergence and maturity of research offers the potential for a paradigm shift in interoperability. This paper explores some of these trends and related technologies. Irrespective of the characteristics of information systems, the development of various industry-contributed ontologies for knowledge and decision layers, may spur self-organizing SOS to increase the ability to sense and respond. Profitability from pervasive use of ontological frameworks and agent-based modeling may depend on the ability to use them through better enterprise and extraprise exchange. Sat, 01 Sep 2007 00:00:00 GMT https://hdl.handle.net/1721.1/102901 2007-09-01T00:00:00Z https://hdl.handle.net/1721.1/102900 Congestion Pricing: A Parking Queue Model Larson, Richard Charles; Sasanuma, Katsunobu Congestion pricing imposes a usage fee on a public resource during times of high demand. Road pricing involves cordoning off a section of the city and imposing a fee on vehicles that enter it. Parking pricing increases the costs of on-street and perhaps off-street parking. Following an historical review, we develop a new queueing model of the parking pricing problem, recognizing that many urban drivers are simply looking for available on-street parking. Often, reducing the number of such “cruising drivers” would reduce urban road congestion dramatically, perhaps as effectively as cordoning off the center city. Wed, 01 Aug 2007 00:00:00 GMT https://hdl.handle.net/1721.1/102900 2007-08-01T00:00:00Z https://hdl.handle.net/1721.1/102899 Pandemic Flu: Yes, We Can Do Something About It! Larson, Richard Charles The emergence of influenza with virulence comparable to the famous 1918-1919 “Spanish Flu” has the potential to kill hundreds of millions of people worldwide. Should we find ourselves being forced to ‘live with the flu,’ it is imperative that we recognize that there are things that we can do – many simple – that may decrease the chance of our loved ones, our co-workers and ourselves becoming infected with the flu. The key is to decrease the number of new infections created by each newly infected person. And this relates to mathematical modeling of the disease, a very simple example of which is shown here. Wed, 01 Aug 2007 00:00:00 GMT https://hdl.handle.net/1721.1/102899 2007-08-01T00:00:00Z https://hdl.handle.net/1721.1/102898 A Novel Engineering Systems Approach for Bioengineering Education: the MIT-Portugal Collaboration Tan, Junjay; Newman, Dava; Cabral, Joaquim M. S.; Mota, Manuel; Nunes da Ponte, Manuel This paper discusses the importance of an engineering systems approach to international bioengineering education and how a new educational research program, the MIT-Portugal Program Bioengineering Systems focus area, aims to develop future global bioengineering leaders. The program, comprising both post-graduate advanced studies and doctoral programs, commences in September 2007. Several other international-collaborative educational and research programs—such as the Cambridge-MIT Institute, the Singapore MIT Alliance, and the Socrates/Erasmus “Erasmus Programme”—offer lessons learned in international collaboration. The MPP Bioengineering Systems program differs from these programs in several respects. The unique collaboration in MPP offers an engineering systems approach, a joint degree offered by three Portuguese universities, and collaborative teaching and research efforts between MIT and Portuguese faculty and students. Fri, 01 Jun 2007 00:00:00 GMT https://hdl.handle.net/1721.1/102898 2007-06-01T00:00:00Z https://hdl.handle.net/1721.1/102897 Protecting the Force: Reducing Combat Vehicle Accidents via Improved Organizational Processes Minami, Nathan A.; Madnick, Stuart E. Despite extraordinary efforts by leaders at all levels throughout the U.S. Army, dozens of soldiers are killed each year as a result of both combat and motor vehicle accidents. The objective of this study is to look beyond the events and symptoms of accidents which normally indicate human error, and instead study the upper-level organizational processes and problems that may constitute the actual root causes of accidents. Critical to this process is identifying critical variables, establishing causality between variables, and quantifying variables that lead to both resilience against accidents and propensities for accidents. After reviewing the available literature we report on our development of a System Dynamics model, which is an analytical model of the system that allows for extensive simulation. The results of these simulations suggest that high-level decisions that balance mission rate and operations tempo with troop availability, careful management of the work-rest cycle for deployed troops, and improvement of the processes for evaluating the lessons learned from accidents, will lead to a reduction in Army combat and motor vehicle accidents. Fri, 01 Jun 2007 00:00:00 GMT https://hdl.handle.net/1721.1/102897 2007-06-01T00:00:00Z https://hdl.handle.net/1721.1/102896 Teaching Systems Thinking to Engineering Undergraduates Using the CLIOS Process Sussman, Joseph M. The introductory science courses taken by engineering undergraduates are usually intensely reductionist in form, silos in physics, chemistry, biology, and so forth. Then, their engineering subjects in the early undergraduate years often tend to be reductionist as well, focusing on a fairly narrow view of the engineering issues practitioners face. Even the design classes often do not account for the socio-technical context for much of the engineering design space that involves a complex interaction between various technologies and the multiple stakeholder views. This paper describes a subject called Engineering System Design, which attempts to create a broader perspective for third-year students in engineering—and indeed in related disciplines in management and planning. It is a combination of lectures on methods related to systems thinking and a semester-long class-wide complex socio-technical system design utilizing these methods and concepts. In recent years, the case has focused on the transportation of spent nuclear fuel to Yucca Mountain, Nevada and related issues in global climate change. Experiences in teaching this class will be discussed and some techniques adopted to enable learning are presented. Tue, 01 May 2007 00:00:00 GMT https://hdl.handle.net/1721.1/102896 2007-05-01T00:00:00Z https://hdl.handle.net/1721.1/102894 Holistic Trinity of Services Sciences: Management, Social, & Engineering Sciences Larson, Richard Charles Services industries comprise about 75% of the economy of developed nations. To design and operate services systems for today and tomorrow, we need to educate a new type of engineer who focuses not on manufacturing but on services. Such an engineer must be able to integrate 3 sciences - management, social and engineering – into her analysis of services systems. Within the context of a new research center at MIT – CESF (Center for Engineering Systems Fundamentals) – we show how newly emerging services systems require such a 3-way holistic analysis. We deliberately select some non-standard services, as many business services such as supply chains have been studied extensively. Sun, 01 Apr 2007 00:00:00 GMT https://hdl.handle.net/1721.1/102894 2007-04-01T00:00:00Z https://hdl.handle.net/1721.1/102893 Unified Theory of Relativistic Identification of Information in a Systems Age: Proposed Convergence of Unique Identification with Syntax and Semantics through Internet Protocol version 6 Datta, Shoumen Palit Austin Unique identification of objects are helpful to the decision making process in many domains. Decisions, however, are often based on information that takes into account multiple factors. Physical objects and their unique identification may be one of many factors. In real-world scenarios, increasingly decisions are based on collective information gathered from multiple sources (or systems) and then combined to a higher level domain that may trigger a decision or action. Currently, we do not have a globally unique mechanism to identify information derived from data originating from objects and processes. Unique identification of information, hence, is an open question. In addition, information, to be of value, must be related to the context of the process. In general, contextual information is of greater relevance in the decision making process or in decision support systems. In this working paper, I shall refer to such information as decisionable information. The suggestion here is to utilize the vast potential of internet protocol version six (IPv6) to uniquely identify not only objects and processes but also relationships (semantics) and interfaces (sensors). Convergence of identification of diverse entities using the globally agreed structure of IPv6 offers the potential to identify 3.4x10[subscript 38] instances based on the fact that the 128-bit IPv6 structure can support 3.4x10[subscript 38] unique addresses. It is not necessary that all instances must be connected to the internet or routed or transmitted simply because an IP addressing scheme is suggested. This is a means for identification that will be globally unique and offers the potential to be connected or routed via the internet. In this working paper, scenarios offer [1] new revenue potential from data routing (P2P traffic track and trace) for telecommunication industries, [2] potential for use in healthcare and biomedical community, [3] scope of use in the semantic web structure by transitioning URIs used in RDF, [4] applications involving thousands of mobile ad hoc sensors (MANET) that demand dynamic adaptive auto-reconfiguration. This paper presents a confluence of ideas. Thu, 01 Mar 2007 00:00:00 GMT https://hdl.handle.net/1721.1/102893 2007-03-01T00:00:00Z https://hdl.handle.net/1721.1/102892 The Use of Information Systems in Collocated and Distributed Teams: A Test of the 24-Hour Knowledge Factory Seshasai, Satwik; Malter, Alan J.; Gupta, Amar Recent academic and policy studies focus on offshoring as a cost-of-labor driven activity that has a direct impact on employment opportunities in the countries involved. This paper broadens this perspective by introducing and evaluating the 24-hour knowledge factory as a model of information systems offshoring that leverages other strategic factors beyond cost savings. A true 24-hour knowledge factory ensures that progress is being made on information systems related tasks at all times of day by utilizing talented information systems professionals around the globe. Many organizations currently implement other variants of offshoring that appear similar but are fundamentally distinct. The typical model is a service provider framework in which an offshore site provides service to the central site, often with two centers and a distinction between a primary center and secondary center. Entire tasks are often outsourced to the lower-cost overseas site and sent back when completed. In contrast, the 24-hour knowledge factory involves continuous and collaborative round-the-clock knowledge production achieved by sequentially and progressively distributing the knowledge creation task around the globe, completing one cycle every 24 hours. Thus, the 24-hour knowledge factory creates a virtual distributed team, in contrast to a team that is collocated in one site, either onshore or offshore. By organizing knowledge tasks in this way, the 24-hour knowledge factory has the potential to work faster, to provide cheaper solutions, and to achieve better overall performance. Previous studies have examined individual teams over time and explored various benefits of distributing work to distant teams, but have not directly compared the effect of collocation versus geographic distribution on the use of information systems and the overall performance over time of two real-world teams working on a similar task in controlled conditions. This paper highlights the concept of the 24-hour knowledge factory and tests the model in a controlled field experiment that directly compares the use of information systems and subsequent performance in collocated and globally distributed software development teams. The central finding is that while collocation versus geographic distribution changes the way teams use information systems and interact at key points during a project, each type of team has the potential to use information systems to leverage its inherent advantages, to overcome disadvantages, and ultimately, to perform equally well. In other words, one organizational structure is not inherently superior nor must structure pre-determine performance. Geographic distance introduces new challenges but these can be overcome – and even leveraged for strategic advantage. In sum, our findings suggest that firms can apply the 24-hour knowledge factory model to transition from a service provider framework in which offshoring is a short-term and unilateral cost-saving tactic to a strategic partnership between centers in which offshoring becomes a core component of a global corporate strategy. Thu, 01 Mar 2007 00:00:00 GMT https://hdl.handle.net/1721.1/102892 2007-03-01T00:00:00Z https://hdl.handle.net/1721.1/102891 Low-Cost Airports for Low-Cost Airlines: Flexible Design to Manage the Risks de Neufville, Richard The paradigm of airport planning and design is changing fundamentally. Low-cost airlines have become significant drivers of airport planning, along with aircraft size and other technical factors. They have different requirements than the “legacy” carriers. They focus on cost and on alternative ways to handle passengers. Now being sizeable participants in the air transport industry, they are influencing airport design. They are central to the proliferation of secondary airports and metropolitan multi-airport systems. They are catalyzing the development of cheaper airport terminals configured internally much differently than traditional designs. These factors lead to the creation of “low-cost airports” for low cost carriers around the “legacy main airports” built to serve the “legacy airlines”. Consistent with economic theory, the competition between the legacy and low cost airlines is extending to their major factors of production, that is, the airports. This competitive reality creates great uncertainty and poses substantial strategic issues for airport and airline managers and planners. The paradigm shift introduces great risks into practice. The paper proposes a flexible design strategy to deal with such uncertainties. This is significantly different from traditional airport master planning. The core element is to build “real options” into the design, which allow the airport owners to match the development to the way the traffic demands unfold in the decades ahead. A review of developments in Portugal illustrates the current risks in airport development, and suggests how airport owners and investors could apply flexible design process to develop a strategy that would manage these uncertainties to maximize expected value. Thu, 01 Mar 2007 00:00:00 GMT https://hdl.handle.net/1721.1/102891 2007-03-01T00:00:00Z https://hdl.handle.net/1721.1/102890 An Algorithm and Metric for Network Decomposition from Similarity Matrices: Application to Positional Analyses Hsieh, Mo-Han; Magee, Christopher L. We present an algorithm for decomposing a social network into an optimal number of structurally equivalent classes. The k-means method is used to determine the best decomposition of the social network for various numbers of subgroups. The best number of subgroups into which to decompose a network is determined by minimizing the intra-cluster variance of similarity subject to the constraint that the improvement in going to more subgroups is better than a random network would achieve. We also describe a decomposability metric that assesses how closely the derived decomposition approaches an ideal network having only structurally equivalent classes. Three well known network data sets were used to demonstrate the algorithm and decomposability metric. These demonstrations indicate the utility of the approach and suggest how it can be used in a complementary way to the Generalized Blockmodeling. Thu, 01 Feb 2007 00:00:00 GMT https://hdl.handle.net/1721.1/102890 2007-02-01T00:00:00Z https://hdl.handle.net/1721.1/102889 Combating System-Level Quality Problems in Complex Product Development Whitney, Daniel E. As products become more complex and their development involves more technologies, people, and companies, it is no longer sufficient to ensure that each part, component, or subsystem is designed and made correctly. Problems that involve many distinct elements can still arise, even if each is designed according to the specifications. Practitioners speak of Murphy’s Law and “sneak paths,” while academics refer to “emergent properties” and “undocumented interactions.” The goal of this paper is to look at this problem from the outside, focusing on Ford and two non-competing companies whose products are also complex: United Technologies and Boeing. Interviews were conducted with senior management and lower level supervisors, focusing on both official processes and anecdotal reports on what works and what does not. Thu, 01 Feb 2007 00:00:00 GMT https://hdl.handle.net/1721.1/102889 2007-02-01T00:00:00Z https://hdl.handle.net/1721.1/102888 Aircraft System Design Graduate Curriculum: A Lifecycle Focus Murman, Earll M.; Lagace, Paul A. Aircraft system design encompasses technical, social and lifecycle topics, and is suitable for graduate studies at the masters level and beyond. Several degree programs in MIT’s School of Engineering offer opportunities for students seeking subjects and degrees in this area. These programs are summarized, and one subject on Aircraft Systems Engineering is introduced as an illustration of content and pedagogy addressing lifecycle topics. Based upon several years of experience of participation in these programs and in offering curriculum, the authors put forward seven observations to stimulate further dialog and progress on this topic. Thu, 01 Feb 2007 00:00:00 GMT https://hdl.handle.net/1721.1/102888 2007-02-01T00:00:00Z https://hdl.handle.net/1721.1/102887 A Classification of Uncertainty for Early Product and System Design de Weck, Olivier L.; Eckert, Claudia Complex systems and products evolve over years to meet new requirements, while applying tried and tested technology. To maximise the reuse of components through the life span, companies need to plan for the changes that they can anticipate, and facilitate accommodation of such changes in the original architecture and design of the system. Methods such as design for flexibility or design for changeability promote incorporation of future uncertain outcomes into system and product design in one way or another. However, the degree to which future product changes can be planned depends on the uncertainties that the system, product or product family is subject to. A deeper understanding of these uncertainties is the focus of this paper. The paper first provides a brief literature survey, and discusses the sources and nature of uncertainty. This is followed by a classification of the types of uncertainties that are often encountered and that should be considered, as well as methods and techniques for modelling these uncertainties for incorporation in system design. The paper also provides examples of uncertainties for a variety of systems and products throughout and concludes with an uncertainty checklist for system architects and product designers. Thu, 01 Feb 2007 00:00:00 GMT https://hdl.handle.net/1721.1/102887 2007-02-01T00:00:00Z https://hdl.handle.net/1721.1/102886 Managing Complexity with the Department of Defense Architecture Framework: Development of a Dynamic System Architecture Model Richards, Matthew G.; Shah, Nirav B.; Hastings, Daniel E.; Rhodes, Donna H. Architecture frameworks are tools for managing system complexity by structuring data in a common language and format. By characterizing the form, function, and rules governing systems, architecture frameworks serve as a communication tool to stakeholder communities with different views of the system and facilitate comparative evaluation across architectures. The goal of this research is to explore the applicability of architecture frameworks to the study of emergent properties of satellites. The U.S. Department of Defense Architecture Framework was selected to achieve this goal given its orientation towards technical systems in contrast to the majority of architecture frameworks focused on business enterprises. Although developed by military planners in the 1990’s to support the acquisition of interoperable information systems, the Department of Defense Architecture Framework can be used to connect operational concepts and capabilities to the technical architecture of any system. While the views of the Department of Defense Architecture Framework are well-defined, little guidance is provided on how the views are to be constructed. Vitech Corporation’s software program CORE,® a systems engineering modeling tool with the ability rapidly to produce architecture views from a common data repository, was employed to complete Department of Defense Architecture Frameworks for the Hubble Space Telescope. Upon characterizing Hubble within this common structure, the value of the Department of Defense Architecture Framework for conducting dynamic quantitative analyses of system architectures was explored. A methodology is proposed and tested for evaluating human and robotic architectures for on-orbit servicing—the extension of the useful life of spacecraft through refueling, upgrading, repair, relocation, et al. In particular, a multi-year servicing campaign is modeled for Hubble including behavioral threads that characterize the Orbiting Observatory, servicing architecture, and science customers. Preliminary results indicate that, when coupled with an executable model, the Department of Defense Architecture Framework can be utilized for dynamic quantitative evaluation of space system architectures. The paper concludes with lessons learned from using the Department of Defense Architecture Framework and proposes improvements for the application of its static views to model-based systems engineering. Thu, 01 Feb 2007 00:00:00 GMT https://hdl.handle.net/1721.1/102886 2007-02-01T00:00:00Z https://hdl.handle.net/1721.1/102885 Superfund: An Assessment of Superfund Site Remedy Selectioin and Implementation Jakobovits, Lisa M.; Karplus, Valerie Jean; Love, Robert E.; Ringo, J. Decker; Sutherland, Timothy A. Since its inception in 1980, the U.S. Environmental Protection Agency’s (EPA) Superfund Program has served as the primary mechanism for coordinating the remediation of sites contaminated with hazardous substances. Although the program has successfully overseen cleanup at hundreds of sites, experts have identified a number of weaknesses in the remedy selection and implementation processes. Our study focuses on two weaknesses that have been identified at individual Superfund sites in the previous literature: Remedy Selection: • Selection of non-permanent remedies over permanent remedies Remedy Implementation: • Inconsistency and non-transparency shown in the documentation of cleanup objectives, site cleanup progress, and problems during remedy implementation Although these weaknesses were well documented in previous literature, our group found little evidence that the underlying cause of these weaknesses had been addressed. Our study adds to the current understanding of these weaknesses by investigating their origins using established policy and engineering systems analysis techniques. We have based our analysis on three Superfund site case studies. We offer several recommendations that address the observed weaknesses in site remedy selection and implementation. Lastly, we include suggestions for areas in which further inquiry may be useful. Mon, 01 Jan 2007 00:00:00 GMT https://hdl.handle.net/1721.1/102885 2007-01-01T00:00:00Z https://hdl.handle.net/1721.1/102884 Strategies for Water Reclamation: The Role of Policy and Technology in the Las Vegas Water Supply Allen, Anna N.; Evans, Christopher W.; Rached, Tarek; Wong, Hsin Min The goals of this report are to: (i) consider Las Vegas' current water reclamation and reuse strategies using a case study framework to examine policy and reclamation technology issues in urban areas; and (ii) using this case study, develop general recommendations and best practices to guide the implementation of water reclamation technologies in the U.S. To accomplish these goals, the committee assessed: (i) the state of the art in water reclamation; (ii) how water management issues and the role of water reclamation are framed in Las Vegas; (iii) the perspectives and alignment of different groups of stakeholders involved in water management issues; and (iv) reclamation technology and policy interactions with respect to public perception, health, environment, regulation and incentives, and security issues. Mon, 01 Jan 2007 00:00:00 GMT https://hdl.handle.net/1721.1/102884 2007-01-01T00:00:00Z https://hdl.handle.net/1721.1/102883 Policy Issues in Implementing Smart Cards in Urban Public Transit Systems Eguchi, Makoto; Fredholm, Susan; Liu, Shan; Ponce de Leon Barido, Paulina; Ye, Jacqueline Many public transportation institutions have been discarding their magnetic strip payment cards or traditional cash-based fee collection systems in favor of automated fare collection systems with smart card technology. Smart cards look like traditional credit cards or ID cards; however, using RFID technology, they allow for contactless payment and identification. Smart cards are becoming increasingly popular among transit agencies primarily because they are convenient for customers, reduce administrative costs for transit agencies, and have the potential of improving the performance of complex transit systems overall. The increased availability and affordability of contactless cards has also contributed to this trend in adoption. Mon, 01 Jan 2007 00:00:00 GMT https://hdl.handle.net/1721.1/102883 2007-01-01T00:00:00Z https://hdl.handle.net/1721.1/102882 Barriers to the Success of 100% Maritime Cargo Container Scanning Cirincione, R.; Cosmas, A.; Low, C.; Peck, J.; Wilds, J. The attacks of September 11, 2001 revealed national security vulnerabilities that had previously not received high level priority in the United States, such as insecure transportation and infrastructure networks. In response, airport security—including passenger and baggage scanning—has been improved. Yet seaport security policies have been slow to change. Five years after 9/11, only 5% of the six million cargo containers that arrive at U.S. seaports are scanned for threats. Mon, 01 Jan 2007 00:00:00 GMT https://hdl.handle.net/1721.1/102882 2007-01-01T00:00:00Z https://hdl.handle.net/1721.1/102881 Pathways to a Trusted Electronic Voting System Connolly, Jeremiah; Levy, Romain; Lindsey, Johnathan; Maro, Judith; Martin, Juan In 2002, Congress passed the Help America Vote Act (HAVA) [1], largely in response to voting irregularities in the 2000 presidential election in Florida. Congress intended that HAVA resolve the lingering public confidence issues arising from inconsistent local election administration procedures, punch card voting machines, and voter registration. With HAVA, Congress authorized payments to the states to implement significant reforms of the voting system. However, the use of electronic voting machines to meet HAVA requirements threatens to damage public confidence in the voting system. Several reports have been published that note security flaws in voting systems in use all over the country [2]. California sued a manufacturer claiming that the company had misrepresented the security of its voting machines and falsified certification information [3]. In Ohio, a battleground state, recount irregularities also resulted in a lawsuit [4]. The public outcry and enormous media attention on these problems prompted Congress's Government Accountability Office (GAO) to launch an investigation [5]. Mon, 01 Jan 2007 00:00:00 GMT https://hdl.handle.net/1721.1/102881 2007-01-01T00:00:00Z https://hdl.handle.net/1721.1/102880 Avian Influenza Pre-Pandemic Procurement: Recommendations for the US Federal Government Bird, Sarah; Heidel, Timothy; McGuinness, Meghan; Sasanuma, Katsunobu; Tan, Junjay Many experts fear that an influenza pandemic will occur in the near future. There is currently much debate about how the US should best prepare. Previous US responses give only minimal guidance as the last major influenza pandemic occurred nearly a century ago—before flu viruses had ever been isolated. Mon, 01 Jan 2007 00:00:00 GMT https://hdl.handle.net/1721.1/102880 2007-01-01T00:00:00Z https://hdl.handle.net/1721.1/102879 U.S. response to an Oil Import Disruption Role of the Federal Government in Light Duty Vehicle Transportation Frazier, Kyle; Lacombe, Romain; Ohama, Dai; Rashid, Faaiza; Rush, Monica This report analyzes technological and policy options for the U.S. federal government response within the light duty vehicle (LDV) sector in the event of a 5 year sustained U.S. oil import curtailment of 5 MMB/D and a global supply disruption of roughly 18 MMB/D. The cause of the oil disruption is damage to the oil production infrastructure in the Middle East; therefore, it is public knowledge that the disruption will be sustained. Mon, 01 Jan 2007 00:00:00 GMT https://hdl.handle.net/1721.1/102879 2007-01-01T00:00:00Z https://hdl.handle.net/1721.1/102878 Identifying the Dynamics of Technology Transition: ADS-B Adoption in the National Airspace System Campos, Norma; Holcombe, Robert; Leybovich, Misha; Szajnfarber, Zoe; Thorsteinsson, Hidigunnur Congestion is a growing problem in the National Airspace System (NAS). Predictions indicate that the NAS, as a whole, will be operating at 75% of capacity by 2010 [2] and that the demand in capacity in air transportation will double within a span of 10 to 35 years [3]. In order for the U.S. to maintain leadership in air transportation and meet the challenges of demand and efficiency of the 21st century, the NAS infrastructure, technology, and procedural strategies need to be modernized [4]. To this end, the FAA plans to implement a cooperative surveillance system called Automatic Dependent Surveillance -- Broadcast, or ADS-B. The surveillance technology and its applications are expected to provide important operational improvements by addressing some of the limitations of the current surveillance system. Mon, 01 Jan 2007 00:00:00 GMT https://hdl.handle.net/1721.1/102878 2007-01-01T00:00:00Z https://hdl.handle.net/1721.1/102877 Linking Historical Roots and Current Methodologies of Engineering Systems Santen, Nidhi R.; Wood, Danielle This paper reviews the historical context and present impact of two sets of literature: the work of Joseph Schumpeter and the field of Strategy Development. Schumpeter’s theories about the impact of technology or innovation on the economy are an important input into modern Engineering Systems (ES) thinking. Meanwhile, Strategy Development is an active contemporary methodology that is relevant to Engineering Systems. Both Schumpeter and the scholars in Strategy Development are concerned with how firms perform, but Schumpeter's approach is descriptive while Strategy Development is prescriptive. The approach in this paper is as follows. It first introduces the theories of Schumpeter on innovation and the major ideas within Strategy Development. Next, two historical reviews are presented. One review looks forward to find the impact that Schumpeter has had on modern fields; the second review looks backward to understand the roots of Strategy Development. These historical reviews are initially done independently. The final section asks whether there are direct historical links between Schumpeter and the scholars or ideas of Strategy Development. The major result of this investigation is that Schumpeter’s influence is widespread as are the roots of Strategy Development. The results also show that the writing of Schumpeter is related to Strategy literature because many of Schumpeter’s ideas have become foundational realities for Strategy Development. Meanwhile, this connection is just one of many for each field, and the link between Schumpeter and Strategy Development does not appear to be the most important. Mon, 01 Dec 2008 00:00:00 GMT https://hdl.handle.net/1721.1/102877 2008-12-01T00:00:00Z https://hdl.handle.net/1721.1/102876 America Disrupted: Dynamics of the Technical Capability Crisis Sturtevant, Daniel Joseph This study investigates the cause of the nearly twenty-five year decline in the percentage of U.S. born undergraduates earning degrees in engineering. This dramatic decline has occurred despite incredibly high pay and low unemployment among individuals holding engineering degrees. On the surface, this situation appears to be violating the basic laws of labor-market supply and demand. A system dynamics model was created to represent the institutional forces and feedback loops present in the real-world system. This model internally represents the economic forces governing the choice to pursue science, technology, engineering, and mathematics (STEM) education, distinguishing features of highly quantitative knowledge that constrain its transmission, and factors determining the overall quality of STEM education in our schools. This work presents a theory that high industry pay for STEM workers and low pay for STEM K-12 teachers directly cause long-term labor shortages that are self perpetuating. A scarcity of STEM workers will cause wages to rise as employers bid up the price of those skills in the short-term. Schools are left with fewer qualified and lower quality teachers. This makes labor shortages worse ten to twenty years down the road. The fact that mathematics knowledge is highly sequential with strong dependencies on past-performance exacerbates the situation. Students who fall behind in mathematics find it nearly impossible to catch up. This work explores many societal shifts that occurred in the 1950‘s through 1980‘s that could have resulted in the perplexing behavior seen from 1985 until the present day. Finally, policy proposals to correct the situation are simulated in the model to test their ability to move the system in a more positive direction. The system is found to exhibit "tipping point" behavior. Small reforms will have negligible impact while larger reforms have the potential to make the system move into a fundamentally better pattern of behavior, but only after considerable delays. Mon, 01 Dec 2008 00:00:00 GMT https://hdl.handle.net/1721.1/102876 2008-12-01T00:00:00Z https://hdl.handle.net/1721.1/102875 The Progress in Wireless Data Transport and its Role in the Evolving Internet Amaya, Mario A.; Magee, Christopher L. The progress of wireless technology through the past 105 years is quantitatively reviewed in this paper. Spectral efficiency and coverage density are both found to increase in a relatively continuous exponential fashion over the entire period with spectral efficiency increasing at about 15% per year and coverage density at about 33% per year. Throughput by wireless technology was not found to follow a single exponential but instead followed an exponential with annual increase of only 5% up to the late 70s and since then (and the introduction of the cellular concept) has followed an exponential with annual increases of greater than 50%. These high rates of progress in the functional performance of wireless technology are an essential enabler for wireless interfaces to become the dominant mode for connecting to the Internet. Sat, 01 Nov 2008 00:00:00 GMT https://hdl.handle.net/1721.1/102875 2008-11-01T00:00:00Z https://hdl.handle.net/1721.1/102874 Technology-Enabled Strategy Development Alternatives for Surface Transportation Dunn, Travis P.; Sussman, Joseph M. This paper examines strategy development processes in surface transportation systems. In the U.S., transportation organizations typically develop strategy through a formal planning process; however, planning is not the only approach for developing strategy. Other approaches include, for example, negotiation, visioning, learning, and consensus-building. Regardless of the particular approach or combination of approaches, strategy development processes have several elements in common. We identify four such elements of particular importance in surface transportation – revenue sources, information sources, temporal scales, and spatial scales – and analyze the impact that advancements in transportation technology have had on each element. While new technologies (e.g. Intelligent Transportation Systems, or ITS) have been applied extensively to improve transportation operations, they have not been used to enable innovative strategy development processes. By understanding more fully the relationships between strategy and technology, organizations may consider adoption of innovative strategy development processes, such as improvements to the planning process or alternatives to planning altogether. Wed, 01 Oct 2008 00:00:00 GMT https://hdl.handle.net/1721.1/102874 2008-10-01T00:00:00Z https://hdl.handle.net/1721.1/102873 Design of Ground Delay Programs Considering the Stakeholder Perspective Hanowsky, Michael; Sussman, Joseph M. A Ground Delay Program (GDP) is an initiative used by the FAA to manage the rate at which aircraft demand arrival at capacity-constrained airports. In this paper, we adapt a framework developed by Mitchell et al. (1997) to identify and determine the importance of the key stakeholders in the design of a GDP. Comparing our results with current practice, we find that passengers and the federal government do not receive consideration that is commensurate with their level of importance. We conclude with suggestions for how the FAA might address this disparity in the design of GDPs. Wed, 01 Oct 2008 00:00:00 GMT https://hdl.handle.net/1721.1/102873 2008-10-01T00:00:00Z https://hdl.handle.net/1721.1/102872 Will Nano-Butlers Work for Micro-Payments? Innovation in Business Services Model may Reduce Cost of Delivering Global Healthcare Services Datta, Shoumen Palit Austin This paper represents an emerging view of personalized care and patient-centric systems approach. It integrates biomedical informatics and business services. A potentially innovative model may evolve from this convergence and may serve as a global template to reduce cost of service. The future of global healthcare may increasingly rely on “sense and then, respond” systems but excluding the instances of exception management, necessary for accidents and emergencies. Solutions suggested in this paper are neither complete nor a panacea but are elements that deserve inclusion in the delivery of healthcare that may combine a portfolio of approaches to suit the needs of the community. As a potential future direction to improve analytics in healthcare, the concept of molecular semantics is proposed. Sun, 01 Jun 2008 00:00:00 GMT https://hdl.handle.net/1721.1/102872 2008-06-01T00:00:00Z https://hdl.handle.net/1721.1/102870 Collaborative Systems Thinking: A survey of literature in search of team-level systems thinking within aerospace teams Lamb, Caroline Twomey This literature review was prepared in support of research investigating team-level systems thinking. Three critical constructs were identified-team, process, and culture-and the pertinent literature is explored in this white paper. The research focused on the aerospace industry, and as such, this white paper uses illustrative examples from the aerospace industry wherever possible. A fourth construct, that of team-level or collaborative systems thinking, is also addressed. This fourth construct is a new construct put forth by the author and her advisors. This white paper is divided into two main section. The first motivates research on team-level systems thinking as a solution to the growing gap between engineering design and engineering analysis. The second section treats the four critical research constructs identified above. For the first three constructs, a definition is provided based on available literature, examples grounded in aerospace are provided, common metrics are introduced, and threats to validity are discussed. For the fourth construct, a discussion of available literature is presented and a construct definition is proposed. Sun, 01 Jun 2008 00:00:00 GMT https://hdl.handle.net/1721.1/102870 2008-06-01T00:00:00Z https://hdl.handle.net/1721.1/102869 Taming the Business Cycles in Commercial Aviation: Trade-space analysis of strategic alternatives using simulation modeling Sgouridis, Sgouris; Sussman, Joseph M.; Weil, Henry Birdseye; Bozdogan, Kirkor We investigate the effectiveness of strategic alternatives that are designed to dampen the cyclicality manifest in the commercial aviation related industries. The constituent enterprises of the commercial aviation system exhibit managerial and operational independence and have diverse value functions that often viewed the enterprises to view their competition as a zero-sum game. We argue that this need not always be the case; in the commercial aviation system both airline and airframe manufacturers constituents would benefit from a steadier influx of aircraft that counters the current situation that is characterized by relatively stable demand growth rate for air travel while airline profitability and aircraft ordering fluctuate intensely. In order to identify and evaluate the symbiotic potential, we use a system dynamics model of commercial aviation. After testing several individual strategic alternatives, we find that capacity management is key to cycle moderation for non-collusive strategies. Comparing faster aircraft deliveries to semi-fixed production schedules among other alternatives shows only the latter alternative to be Pareto efficient. Thu, 01 May 2008 00:00:00 GMT https://hdl.handle.net/1721.1/102869 2008-05-01T00:00:00Z https://hdl.handle.net/1721.1/102868 A Comparison of GDP-Based Productivity in Ambulatory & Inpatient Healthcare: 1998-2005 Hartzband, David A comparison of GDP-based productivity in the ambulatory and inpatient (hospitals and residential treatment centers) healthcare segments shows that labor productivity, measured as GDP dollar contribution per compensation dollars, hours worked and full-time equivalent employees was strong in both actual value and in per cent gain (1998-2005). The actual values were higher in ambulatory with GDP contribution per hours worked ranging from $0.04-$0.06 (24% gain), per dollar of compensation ranging from $1.41 to $1.48 (4% gain) and per FTE from $71,000 to $94,000 (25% gain) as opposed to $0.02 to $0.03 (3% gain), $1.10 to $1.13 (3% gain) and $38,000 to $52,000 (42% gain) for inpatient healthcare. In contrast, capital efficiency was static for both segments over this period indicating that the use of capital was ineffective. Total Factor Productivity (TFP) was also calculated and showed a similar pattern with ambulatory healthcare having higher TFP throughout the period, but neither healthcare segment showing any gain (or loss) in TFP. The two segments have different profiles for the factors influencing TFP with inpatient healthcare having made both some R&D and substantial technology investments, mainly in medical devices. Neither segment has made large organizational or work process changes, and it appears that substantial, additional productivity gains could be made as these factors, R&D investment, technology acquisition and adoption, work process and organizational redesign, are emphasized. Tue, 01 Apr 2008 00:00:00 GMT https://hdl.handle.net/1721.1/102868 2008-04-01T00:00:00Z https://hdl.handle.net/1721.1/102867 Growing Towards a Sustainable Biofuel Future: A Comprehensive Policy Strategy for Navigating Tradeoffs and Stakeholder Interests in U.S. Agriculture Donohoo, Pearl; MacKenzie, Don; McAulay, Jeff; Pertuze, Julio; Stark, Addison Rapid growth of biofuels production in the United States is reshaping the agricultural industry, delivering both benefits and conflict among stakeholders. Routes forward on biofuels production should be viewed in the context of economic, land use, environmental, and energy security tradeoffs and their potential impacts in the future. This report discusses the current, emerging, and prospective conflicts arising from increased biofuels production, recommends policies to resolve these conflicts, and identifies likely areas of support and opposition from stakeholder groups. The report focuses heavily on ethanol, because ethanol accounts for 95 percent of U.S. biofuels production (Worldwatch 2006); however, many of the trade-offs and recommendations identified in the report can and should be applied to biofuels more generally. This report does not attempt to assess whether or not biofuels are the best option for transportation fuel use. Rather, it accepts that current mandates, policies, and market conditions will result in increased biofuel production and proposes policies to support growth in more economically and environmentally sustainable manners. Sat, 01 Mar 2008 00:00:00 GMT https://hdl.handle.net/1721.1/102867 2008-03-01T00:00:00Z https://hdl.handle.net/1721.1/102865 GDP-Based Productivity in Ambulatory Healthcare: A Comparison with other Industry Segments, 1998-2005 Hartzband, David Few studies have focused on productivity in healthcare, let alone in ambulatory healthcare. Measurement of productivity in various healthcare segments has generally shown that productivity has either decreased (over some time period) or has increased more slowly than in other industry segments. This study shows that labor productivity has increased in ambulatory healthcare between 1998 and 2005 (by ~24%), but that capital efficiency has not changed over that time period. The study compared this result with the same measurements in the auto and information industry segments (as defined by the Bureau of Economic Analysis) and found that labor productivity gains were highest in the information industry (34%) and lowest in auto (6%), and that capital efficiency increased 8% in the information industry but decreased 7% in auto. The study also found a strong linkage between changes in gross domestic product components for value-added and gross output and both labor and capital inputs in ambulatory healthcare. This linkage was not found in either of the other two industry segments investigated. This linkage implies that labor and capital input account for close to all of the productivity gains measured in ambulatory healthcare, but that other factors, such as labor quality, work process and structural reorganization, research and development investment and adoption of new technologies are not affecting this gain in productivity the way they may be in auto and the information industry. This result implies that addressing these factors may increase productivity in ambulatory healthcare even more than has been the case from labor and capital input increases. Fri, 01 Feb 2008 00:00:00 GMT https://hdl.handle.net/1721.1/102865 2008-02-01T00:00:00Z https://hdl.handle.net/1721.1/102864 Revisiting R[subscript 0], the Basic Reproductive Number for Pandemic Influenza Larson, Richard Charles This paper focuses on a fundamental input parameter for most existing mathematical models of pandemic influenza, the ‘basic reproductive number R[subscript 0],’ defined to be the mean number of new influenza infections created by a newly infected person in a population of all susceptible people. We argue that R[subscript 0] is limited in policy and scientific value as is any single parameter attempting to characterize a complex probabilistic process. In particular, we demonstrate by simple logic that R[subscript 0] does not exist as a separate ‘constant of a particular influenza,’ but rather its value is determined by social context and behavioral patterns as well as by the “physics’’ of the influenza virus. To the extent that R[subscript 0] is useful, it is best viewed as an output of a modeling analysis, not an input. But with R[subscript 0] being the mean of a random variable, much more information is contained in the entire probability distribution. With this view, we show – again by simple arguments – that R[subscript 0] can be greater than 1.0 and still, contrary to popular belief, the probability of an exponentially growing pandemic may be arbitrarily small. Finally, we show that attempts to estimate R[subscript 0] from data of previous pandemics is fraught with methodological complexities, due primarily to heterogeneities in the population that cause super-spreaders and socially active people to be the first propagators of the disease. Unless one is careful, statistical estimates of R[subscript 0] based on early exponential growth of reported cases may be significantly upwardly biased. Fri, 01 Feb 2008 00:00:00 GMT https://hdl.handle.net/1721.1/102864 2008-02-01T00:00:00Z https://hdl.handle.net/1721.1/102863 Auto ID Paradigm Shifts from Internet of Things to Unique Identification of Individual Decisions in System of Systems Datta, Shoumen Palit Austin Return on investment (ROI) from radio frequency (RF) based tools of identification may increase with the diffusion of frequency agnostic modes of radio frequency identification (RFID), such as, ultrawideband (UWB). Similarly, fixed frequency readers may be replaced with interrogators that can operate in any frequency, such as software defined radio (SDR). However, mere identification of objects provides data that may not be useful unless the process of data acquisition is further linked to systems where the data can be analysed and useful information extracted. This evolution remains incomplete because data about objects is only a small segment of necessary information. Global businesses and systems, such as healthcare, demand much more than object data. Often processes and plans as well as prior decisions are taken into account when deciding on a future course of action or may be the next step in a transaction. Current practice of auto id, although useful in some instances, remains only a small part of what is necessary for identification of information in complex system of systems. Identification, therefore, must encompass the ability both tangible and intangible elements that contribute to decisions. The unique “address” must be preserved during information exchange and decision support between system of systems. Fri, 01 Feb 2008 00:00:00 GMT https://hdl.handle.net/1721.1/102863 2008-02-01T00:00:00Z https://hdl.handle.net/1721.1/102862 Design and Management of Flexible Transportation Networks Through the use of Intelligent Transportation Systems (ITS) McConnell, Joshua; Sussman, Joseph M. Designing a flexible system with real options is a method for managing uncertainty. In this research, Intelligent Transportation System (ITS) capabilities were used to create a flexible transportation system, capable of coping with multiple uncertainties. Specifically, HOT, BRT and TOT managed lanes were examined in a case study centered in Houston, Tx, to determine the benefits of flexibility these capabilities provide. A qualitative analysis procedure utilizing regional traffic demand modeling and real options analysis was utilized to assess these benefits. It was found that ITS managed lanes can be configured in multiple ways to create flexibility in transportation systems, each of which provides value when dealing with uncertainty. Fri, 01 Feb 2008 00:00:00 GMT https://hdl.handle.net/1721.1/102862 2008-02-01T00:00:00Z https://hdl.handle.net/1721.1/102861 A Portfolio Approach for Purchasing Systems: Impact of Switching Point Hilmola, Olli-Pekka; Ma, Hongze; Datta, Shoumen Palit Austin In operations management different ordering policies, such as, economic order quantity, lot for lot and periodic ordering, are used in various combinations without deeper considerations for the likely consequences on cash flow and profitability. The success of these techniques is analyzed through inventory levels and/or total cost. In this paper, we present results of simulation which uses three different product groups with varying demand characteristics, changing product margins and also considers product quality failures (due to ordering, engineering change or customer requests). Based on our results, we suggest a portfolio approach where lot for lot policy may be useful in an early phase of the product life-cycle and later it may be an advantage to change over to economic order quantity (EOQ) based ordering. However, demand sustainability and failure rates create instances where orders in larger economical lots may reduce profitability. Therefore, manufacturing may benefit from a portfolio of different purchase order policies and may evaluate the successful balance of policies using cash flow as a parameter. Accuracy of demand forecasting is vital to switching point estimation. Further research on real-world applications of advanced forecasting tools is advocated as well as a framework to develop the portfolio for intelligent purchasing systems. Tue, 01 Jan 2008 00:00:00 GMT https://hdl.handle.net/1721.1/102861 2008-01-01T00:00:00Z https://hdl.handle.net/1721.1/102860 Understanding Complexity: Dynamic Analysis of Combat Vehicle Accidents Minami, Nathan A.; Madnick, Stuart E. Dozens of U.S. soldiers are killed each year as a result of both combat and motor vehicle accidents. The objective of this study is to look beyond the events and symptoms of accidents which normally indicate human error, and instead study the complex and poorly understood upper-level organizational processes and problems that may constitute the actual root causes of accidents – this is particularly challenging because the causes often involve nonlinear dynamic phenomena and have behaviors that are counter-intuitive to normal human thinking, these are often called “wicked” problems. After reviewing the available literature, a System Dynamics model was created to provide an analytical model of this multifaceted system that allows for extensive simulation. The results of these simulations suggest that high-level decisions that balance mission rate and operations tempo with troop availability, careful management of the work-rest cycle for deployed troops, and improvement of the processes for evaluating the lessons learned from accidents, will lead to a reduction in Army combat and motor vehicle accidents. Tue, 01 Jan 2008 00:00:00 GMT https://hdl.handle.net/1721.1/102860 2008-01-01T00:00:00Z https://hdl.handle.net/1721.1/102858 Evaluating and Aggregating Data Believability across Quality Sub-Dimensions and Data Lineage Pratt, Nicolas; Madnick, Stuart E. Data quality is crucial for operational efficiency and sound decision making. This paper focuses on believability, a major aspect of data quality. The issue of believability is particularly relevant in the context of Web 2.0, where mashups facilitate the combination of data from different sources. Our approach for assessing data believability is based on provenance and lineage, i.e. the origin and subsequent processing history of data. We present the main concepts of our model for representing and storing data provenance, and an ontology of the sub-dimensions of data believability. We then use aggregation operators to compute believability across the sub-dimensions of data believability and the provenance of data. We illustrate our approach with a scenario based on Internet data. Our contribution lies in three main design artifacts (1) the provenance model (2) the ontology of believability subdimensions and (3) the method for computing and aggregating data believability. To our knowledge, this is the first work to operationalize provenance-based assessment of data believability. Tue, 01 Jan 2008 00:00:00 GMT https://hdl.handle.net/1721.1/102858 2008-01-01T00:00:00Z https://hdl.handle.net/1721.1/102857 Measuring Data Believability: A Provenance Approach Pratt, Nicolas; Madnick, Stuart E. Data quality is crucial for operational efficiency and sound decision making. This paper focuses on believability, a major aspect of quality, measured along three dimensions: trustworthiness, reasonableness, and temporality. We ground our approach on provenance, i.e. the origin and subsequent processing history of data. We present our provenance model and our approach for computing believability based on provenance metadata. The approach is structured into three increasingly complex building blocks: (1) definition of metrics for assessing the believability of data sources, (2) definition of metrics for assessing the believability of data resulting from one process run and (3) assessment of believability based on all the sources and processing history of data. We illustrate our approach with a scenario based on Internet data. To our knowledge, this is the first work to develop a precise approach to measuring data believability and making explicit use of provenance-based measurements. Tue, 01 Jan 2008 00:00:00 GMT https://hdl.handle.net/1721.1/102857 2008-01-01T00:00:00Z https://hdl.handle.net/1721.1/102856 Enabling Global Price Comparison with Semantic Integration of Web Data Zhu, Hongwei; Madnick, Stuart E.; Siegel, Michael D. “Sell Globally” and “Shop Globally” have been seen as a potential benefit of web-enabled electronic business. One important step toward realizing this benefit is to know how things are selling in various parts of the world. A global price comparison service would address this need. But there have not been many such services. In this paper, we use a case study of global price dispersion to illustrate the need and the value of a global price comparison service. Then we identify and discuss several technology challenges, including semantic heterogeneity, in providing a global price comparison service. We propose a mediation architecture to address the semantic heterogeneity problem, and demonstrate the feasibility of the proposed architecture by implementing a prototype that enables global price comparison using data from web sources in several countries. Tue, 01 Jan 2008 00:00:00 GMT https://hdl.handle.net/1721.1/102856 2008-01-01T00:00:00Z https://hdl.handle.net/1721.1/102855 Semantic Integration Approach to Efficient Business Data Supply Chain: Integration Approach to Interoperable XBRL Zhu, Hongwei; Madnick, Stuart E. As an open standard for electronic communication of business and financial data, XBRL has the potential of improving the efficiency of the business data supply chain. A number of jurisdictions have developed different XBRL taxonomies as their data standards. Semantic heterogeneity exists in these taxonomies, the corresponding instances, and the internal systems that store the original data. Consequently, there are still substantial difficulties in creating and using XBRL instances that involve multiple taxonomies. To fully realize the potential benefits of XBRL, we have to develop technologies to reconcile semantic heterogeneity and enable interoperability of various parts of the supply chain. In this paper, we analyze the XBRL standard and use examples of different taxonomies to illustrate the interoperability challenge. We also propose a technical solution that incorporates schema matching and context mediation techniques to improve the efficiency of the production and consumption of XBRL data. Tue, 01 Jan 2008 00:00:00 GMT https://hdl.handle.net/1721.1/102855 2008-01-01T00:00:00Z https://hdl.handle.net/1721.1/102854 Lean Aerospace Engineering Murman, Earll M. A framework for Lean Engineering is presented, based upon observational findings from a decade of research in the aerospace domain, published works on Toyota and Southwest Airlines, and practitioner input. The framework is illustrated with examples drawn from aircraft and other aerospace applications. Lean Engineering is not totally new to aerospace, and it continues to evolve. Future challenges are briefly summarized. Tue, 01 Jan 2008 00:00:00 GMT https://hdl.handle.net/1721.1/102854 2008-01-01T00:00:00Z https://hdl.handle.net/1721.1/102853 Disciplinary Links Between Scientific Management and Strategy Development Cameron, Bruce Gregory; Pertuze, Julio A. We investigate the incidence of links between the historical discipline of scientific management and the modern study of strategy development. Despite a century’s separation, these two disciplines share noticeable commonality in their trajectories and their approach to management. We conducted a forward search of the impact of scientific management, finding influences on accounting, human resource management, and the creation of the modern MBA. We then conducted a backward search of the roots of strategy development, including a novel directed reference tree search by citation count. We find overlap between these two searches in organization theory, operations research, and industrial psychology. Further, we identify disciplinary oscillation between quantitative process studies and context-based ethnographic research in the study of management questions. Tue, 01 Dec 2009 00:00:00 GMT https://hdl.handle.net/1721.1/102853 2009-12-01T00:00:00Z https://hdl.handle.net/1721.1/102852 Financial Development, Gender and Entrepreneurship Llussa, Fernanda Female entrepreneurs are much less frequent than male entrepreneurs. In this paper we investigate a possible culprit: access to financial services. We use a dataset with entrepreneurship rates by opportunity and by need from the Global Entrepreneurship Monitor and indicators of financial institutions from Beck, Demirgüç-Kunt and Levine (2000) for 41 developed and developing countries from 2001 to 2004. Our conclusions are that financial development, though generally encouraging entrepreneurial activity, is unlikely, by itself, to contribute to bring male and female entrepreneurship rates closer together. Moreover, our results suggest that it is entrepreneurship by need that is most affected by financial development, suggesting that the possible more complex aspects of evaluating projects associated with market or technological opportunities are not overcome by aggregate financial development and need more specific measures. Thu, 01 Oct 2009 00:00:00 GMT https://hdl.handle.net/1721.1/102852 2009-10-01T00:00:00Z https://hdl.handle.net/1721.1/102851 Experiences and Challenges with using CERT Data to Analyzes Madnick, Stuart E.; Li, Xitong; Choucri, Nazli With the increasing interconnection of computer networks and sophistication of cyber attacks, it is important to understand the dynamics of such situations, especially in regards to cyber international relations. The Explorations in Cyber International Relations (ECIR) Data Dashboard Project is an initiative to gather worldwide cybersecurity data publicly provided by nation-level Computer Emergency Response Teams (CERTs) and to provide a set of tools to analyze the cybersecurity data. The unique contributions of this paper are: (1) an evaluation of the current state of the diverse nation-level CERT cybersecurity data sources, (2) a description of the Data Dashboard tool developed and some interesting analyses from using our tool, and (3) a summary of some challenges with the CERT data availability and usability uncovered in our research. Thu, 01 Oct 2009 00:00:00 GMT https://hdl.handle.net/1721.1/102851 2009-10-01T00:00:00Z https://hdl.handle.net/1721.1/102850 A Framework for Technology Forecasting and Visualization Woon, Wei Lee; Henschel, Andreas; Madnick, Stuart E. This paper presents a novel framework for supporting the development of well-informed research policies and plans. The proposed methodology is based on the use of bibliometrics; i.e., analysis is conducted using information regarding trends and patterns of publication. Information thus obtained is analyzed to predict probable future developments in the technological fields being studied. While using bibliometric techniques to study science and technology is not a new idea, the proposed approach extends previous studies in a number of important ways. Firstly, instead of being purely exploratory, the focus of our research has been on developing techniques for detecting technologies that are in the early growth phase, characterized by a rapid increase in the number of relevant publications. Secondly, to increase the reliability of the forecasting effort, we propose the use of automatically generated keyword taxonomies, allowing the growth potentials of subordinate technologies to aggregated into the overall potential of larger technology categories. As a demonstration, a proof-of-concept implementation of each component of the framework is presented, and is used to study the domain of renewable energy technologies. Results from this analysis are presented and discussed. Thu, 01 Oct 2009 00:00:00 GMT https://hdl.handle.net/1721.1/102850 2009-10-01T00:00:00Z https://hdl.handle.net/1721.1/102849 Approach and Preliminary Results for Early Growth Technology Analysis Ziegler, Blaine; Firat, Ayse Kaya; Madnick, Stuart E.; Woon, Wei Lee; Camina, Steven; Li, Clare; Fogg, Erik Even experts cannot be fully aware of all the promising developments in broad and complex fields of technology, such as renewable energy. Fortunately, there exist many diverse sources of information that report new technological developments, such as journal publications, news stories, and blogs. However, the volume of data contained in these sources is enormous; it would be difficult for a human to read and digest all of this information – especially in a timely manner. This paper describes a novel application of technology mining techniques to these diverse information sources to study, visualize, and identify the evolution of promising new technologies – a challenge we call “early growth technology analysis”. For the work reported herein, we use as inputs information about millions of published documents contained in sources such as SCIRCUS, Inspec, and Compendex. We accomplish this analysis through the use of bibliometric analysis, consisting of three key steps: 1. Extract related keywords (from keywords in articles) 2. Determine the annual occurrence frequencies of these keywords 3. Identify those exhibiting rapid growth, particularly if starting from a low bas To provide a focus for the experiments and subsequent discussions, a pilot study was conducted in the area of “renewable energy,” though the techniques and methods developed are neutral to the domain of study. Preliminary results and conclusions from the case study are presented and are discussed in the context of the effectiveness of the proposed methodology. Thu, 01 Oct 2009 00:00:00 GMT https://hdl.handle.net/1721.1/102849 2009-10-01T00:00:00Z https://hdl.handle.net/1721.1/102848 Engineering Responses to Pandemics Larson, Richard Charles; Nigmatulina, Karima R. Focusing on pandemic influenza, this chapter approaches the planning for and response to such a major worldwide health event as a complex engineering systems problem. Action-oriented analysis of pandemics requires a broad inclusion of academic disciplines since no one domain can cover a significant fraction of the problem. Numerous research papers and action plans have treated pandemics as purely medical happenings, focusing on hospitals, health care professionals, creation and distribution of vaccines and anti-virals, etc. But human behavior with regard to hygiene and social distancing constitutes a first-order partial brake or control of the spread and intensity of infection. Such behavioral options are “non-pharmaceutical interventions.” (NPIs) The chapter employs simple mathematical models to study alternative controls of infection, addressing a well-known parameter in epidemiology, R0, the “reproductive number,” defined as the mean number of new infections generated by an index case. Values of R0 greater than 1.0 usually indicate that the infection begins with exponential growth, the generation-to-generation growth rate being R0. R0 is broken down into constituent parts related to the frequency and intensity of human contacts, both partially under our control. It is suggested that any numerical value for R0 has little meaning outside the social context to which it pertains. Difference equation models are then employed to study the effects of heterogeneity of population social contact rates, the analysis showing that the disease tends to be driven by high frequency individuals. Related analyses show the futility of trying geographically to isolate the disease. Finally, the models are operated under a variety of assumptions related to social distancing and changes in hygienic behavior. The results are promising in terms of potentially reducing the total impact of the pandemic. Sat, 01 Aug 2009 00:00:00 GMT https://hdl.handle.net/1721.1/102848 2009-08-01T00:00:00Z https://hdl.handle.net/1721.1/102847 ESD and Health Care Systems: some strategic considerations de Weck, Alain Proper health care delivery to a growing but aging population is becoming one of the most challenging tasks of our time. It becomes also one of the most complex. Although many tools are at hand, grand designs and implementation systems are mostly lacking. In the industrialized countries, requests for optimal medical care and the demographic evolution towards longer life have led to different health care systems but all of them may be characterized as more or less dysfunctional (see below). In many developing countries, the gaps caused by the lack of health care infrastructure and education and by economic backwardness are becoming increasingly apparent. On the other hand, the relatively new approach of engineering for solution and optimization of various complex problems, such as energy, infrastructures, transportation, manufacturing or environmental protection leads us to ask whether the logical and analytical tools developed in complex systems engineering could also be applied to the whole or parts of the health care field. A brief discussion of that issue is the purpose of this memorandum. Sat, 01 Aug 2009 00:00:00 GMT https://hdl.handle.net/1721.1/102847 2009-08-01T00:00:00Z https://hdl.handle.net/1721.1/102846 COIM: An Object-Process Based Method for Analyzing Architectures of Complex, Interconnected, Large-Scale Socio-Technical Systems Osorio, Carlos A.; Dori, Dov; Sussman, Joseph M. There is growing evidence of the relevance of human behavioral factors in the success of development of new products, processes and services. The evidence is even clearer when the forces affecting the development and evolution of longlived, large, and open complex socio-technical systems are researched. Methods that study the architecture of such types of systems can help scholars and practitioners to better understand, manage, and develop socio-technical systems. We propose an approach and a method to address these needs that is grounded in the theory of systems architecture and builds on the strengths of Object Process Methodology (OPM) and the process for representing Complex Large-scale Interconnected Open Socio-technical (CLIOS) systems. We do so by integrating these methods into the CLIOS-OPM Integrated Method (COIM). COIM is conducive to studying a system’s architecture and its evolution, as it is enhanced by a set of qualitative methods for answering questions about the reasons (why) and process (how) of change in human-made systems over time. Sat, 01 Aug 2009 00:00:00 GMT https://hdl.handle.net/1721.1/102846 2009-08-01T00:00:00Z https://hdl.handle.net/1721.1/102845 Use of Collaborative Technologies and Knowledge Sharing in Co-located and Distributed Teams: Towards the 24-Hour Knowledge Factory Gupta, Amar; Mattarelli, Elisa; Seshasai, Satwik; Broschak, Joseph The relocation of knowledge work to emerging countries is leading to an increasing use of Globally Distributed Teams (GDT) engaged in complex tasks. In the present study, we investigate a particular type of GDT working ‘around the clock’: the 24 hours knowledge factory (Gupta, 2008). Adopting the productivity perspective on knowledge sharing (Haas and Hansen, 2005, 2007), we develop 11 hypotheses to compare technology use, knowledge sharing processes, and performance of a 24 hours knowledge factory with a co-located team. We conducted a quasi-experiment in IBM and collected both quantitative and qualitative data, over a period of 12 months, on a GDT and a co-located team. Both teams were composed of the same number of professionals, provided with the same technologies, engaged in similar tasks, and given similar deadlines. We found that they differed in their use of technologies and in knowledge sharing processes, but not in efficiency and quality of outcomes. We show how the co-located team and the GDT enacted a knowledge codification strategy and a personalization strategy respectively; in each case, they grafted elements of the other strategy in order to attain both knowledge re-use and creativity. We conclude by discussing theoretical contributions to knowledge sharing and GDT literatures, and by highlighting managerial implications to those organizations interested in developing a fully functional 24 hour knowledge factory. Sat, 01 Aug 2009 00:00:00 GMT https://hdl.handle.net/1721.1/102845 2009-08-01T00:00:00Z https://hdl.handle.net/1721.1/102844 The 24-Hour Knowledge Factory Paradigm: The Evolving Model for Offshoring based on Strategic, Economic, Legal, Health, Technical, and Other Considerations Gupta, Amar The 24-Hour Knowledge Factory paradigm involves 3 (or more) collaborating centers, each located in a different continent. Individuals at each center work from 9 am to 5 pm in that country, and then pass the work-in-progress to the next collaborating center to enable round-theclock performance in a manner somewhat akin to the deployment of three shifts in the manufacturing sector. The 24-Hour Knowledge Factory is relevant for structured and semi-structured applications in many knowledge-based industries including accounting, legal, design, and development. There is a growing array of examples from healthcare and other domains where off-site professionals have been able to provide better results than on-site professionals, thereby validating that many tasks can be more effectively performed using the 24-Hour Knowledge Factory approach. The gradual adoption of this paradigm is motivated by several considerations. In 2007, the World Health Organization concluded that working at night is a probable cause of breast cancer in women and prostate cancer in men. Attempts by US state governments and even the federal government to discourage outsourcing are unlikely to succeed for multiple reasons, and the notion of “hybrid outsourcing” will gain momentum over time. Plus there are the advantages of developing products and services in a shorter timeframe; furthermore, these products and services can command broader appeal in the global marketplace. A detailed study was conducted at IBM to compare the performance of a co-located team and a distributed team, and the performance of the latter team exceeded initial expectations. The key results from this study will be discussed in this session. Sat, 01 Aug 2009 00:00:00 GMT https://hdl.handle.net/1721.1/102844 2009-08-01T00:00:00Z https://hdl.handle.net/1721.1/102843 Towards quantification of the Role of Materials Innovation in overall Technological Development Magee, Christopher L. This report develops a method for quantitatively assessing the role of materials innovation in overall technological development. The report demonstrates the method for one specific case and defines the key requirements to use it in a number of other cases. The new method involves the comparative examination of overall technical capability metrics with performance metrics at more detailed levels of progress where materials and process innovation dominates the progress. This analysis is supplemented by exploration of the specific technical capabilities utilized in technological development areas of interest. It is specifically found that about 2/3 of the total progress in computation over the past 40 years has been due to materials/process innovations. It is also found that making reasonably reliable estimates in other functional areas such as energy storage, information transmission, etc. could be possible if more attention were paid to the development and collection of technical progress metrics at the level of materials and processes (such as Moore’s Law has done for information transformation). Examination of what is known leads to three other key (but more speculative) findings: 1) Materials/process innovation contributes at least 20% of the progress in all areas examined; 2) The contribution of materials/process innovations in energy storage are possibly 80% or higher; 3) The relative contribution of materials/process innovation to overall technological progress has grown in the past few decades. Wed, 01 Jul 2009 00:00:00 GMT https://hdl.handle.net/1721.1/102843 2009-07-01T00:00:00Z https://hdl.handle.net/1721.1/102842 A New Model Of Cascades On Random Networks With A Threshold Rule Fundamentals Whitney, Daniel E. Percolation or cascades on random networks are typically analyzed using generating functions. This approach requires that the network be assumed infinite and weakly connected. These assumptions are not obeyed by real or simulated networks on which this theory is often used. In this paper we offer a theory that assumes a finite network with arbitrary average nodal degree and apply it to the case where cascades follow a threshold rule, that is, that a node will change state (“flip”) only if a fraction, exceeding a given threshold, of its neighbors has changed state previously. The model is a dynamic Markov model whose state transition matrix, recalculated after each step, records the probability that a node of degree k has i flipped neighbors after j steps in the cascade’s evolution. The model reproduces a number of previously unreported behaviors observed in simulations. These include the ability to create cascades in a domain previously predicted to forbid cascades as well as a “near death” behavior in which cascades initially appear about to die but later explode. Cascades in the “no cascades” region require a sufficiently large seed of initially flipped nodes or else the cascade will die out. The model and simulations are compared with a foundational paper by Watts which used the generating function theory. Thu, 01 Oct 2009 00:00:00 GMT https://hdl.handle.net/1721.1/102842 2009-10-01T00:00:00Z https://hdl.handle.net/1721.1/102841 White Paper On Novel H1N1: Prepared for the MIT Center for Engineering Systems Fundamentals Barry, John M. This paper is an historical and policy primer for one to prepare for a severe flu pandemic - which is virtually guaranteed to happen at some time in the future. The paper provides actionable knowledge, gleaned from past flu pandemics and from recent science, to reduce the chance of you and your loved ones from contracting the flu. The paper discusses both the new novel H1N1 flu virus and the more lethal H5 N1 ("bird flu") virus. In discussing the future of H1N1, the author says, "Three of the preceding four pandemics, 1889, 1918, and 1957, show clear evidence of some fairly intense but sporadic initial local outbreaks scattered around the world. The novel H1N1 virus seems thus far to be following the pattern of those three pandemics, and it seems highly likely that it will return in full flower." The author projects that a full fledged global pandemic could cut global GDP by up to 4 to 6 percent, and that companies must now prepare for supply chain disruptions, even if only the milder H1N1 becomes the prevalent flu. An individual's behavioral changes with social distancing and hygienic steps can dramatically reduce the chance of contracting the flu. Wed, 01 Jul 2009 00:00:00 GMT https://hdl.handle.net/1721.1/102841 2009-07-01T00:00:00Z https://hdl.handle.net/1721.1/102840 Measuring and Understanding Hierarchy asMeasuring and Understanding Hierarchy as an Architectural Element in Industry Sectors an Architectural Element in Industry Sectors Luo, Jianxi; Whitney, Daniel E.; Baldwin, Carliss Y.; Magee, Christopher L. Hierarchy is a generic structure in which levels are asymmetrically ordered. In an industry setting, classic supply chains display strict hierarchy, whereas clusters of firms have linkages going in many different directions. Previous theory has often assumed the existence of the hierarchical relationships among firms and empirical work has focused on a single level of an industry or bilateral relationships. However, quantitative evidence on the deep hierarchy in large industrial sectors is lacking. In this paper, we develop metrics and methods to define and measure the degree of hierarchy in transactional relationships among firms, and apply the methods to two large industrial sectors in Japan: automotive and electronics. We compiled the networks of firms connected by transactional relationships. Our empirical analysis shows that the automotive sector exhibits a higher degree of hierarchy than the electronics sector. We further analyze the differences in hierarchy using a simulation model based on transaction breadth and transaction specificity. The empirical measurement and model analysis together indicate that it is the low transaction specificity that drives down the degree of hierarchy in the electronics sector. Differences in transaction patterns in turn may result from the differences in the power level of underlying technologies, which affect product specificity and asset specificity. Thus, the degree of hierarchy in an industry sector may be traced back to fundamental properties of the underlying technologies. Mon, 01 Jun 2009 00:00:00 GMT https://hdl.handle.net/1721.1/102840 2009-06-01T00:00:00Z https://hdl.handle.net/1721.1/102839 Framework for the Analysis of the Adaptability, Extensibility, and Scalability of Semantic Information Integration and the Context Mediation Approach Gannon, Thomas; Madnick, Stuart E.; Moulton, Allen; Sabbouh, Marwan; Siegel, Michael D.; Zhu, Hongwei Technological advances such as Service Oriented Architecture (SOA) have increased the feasibility and importance of effectively integrating information from an ever widening number of systems within and across enterprises. A key difficulty of achieving this goal comes from the pervasive heterogeneity in all levels of information systems. A robust solution to this problem needs to be adaptable, extensible, and scalable. In this paper, we identify the deficiencies of traditional semantic integration approaches. The COntext INterchange (COIN) approach overcomes these deficiencies by declaratively representing data semantics and using a mediator to create the necessary conversion programs from a small number of conversion rules. The capabilities of COIN is demonstrated using an example with 150 data sources, where COIN can automatically generate the over 22,000 conversion programs needed to enable semantic interoperability using only six parametizable conversion rules. This paper presents a framework for evaluating adaptability, extensibility, and scalability of semantic integration approaches. The application of the framework is demonstrated with a systematic evaluation of COIN and other commonly practiced approaches. Wed, 01 Apr 2009 00:00:00 GMT https://hdl.handle.net/1721.1/102839 2009-04-01T00:00:00Z https://hdl.handle.net/1721.1/102838 Technology Forecasting Using Data Mining and Semantics: First Annual Report Woon, Wei Lee; Madnick, Stuart E.; Firat, Ayse; Ziegler, Blaine; Seshasai, Satwik The planning and management of research and development is a challenging process which is compounded by the large amounts of information which is available. The goal of this project is to mine science and technology databases for patterns and trends which facilitate the formation of research strategies. Examples of the types of information sources which we exploit are diverse and include academic journals, patents, blogs and news stories. The intended outputs of the project include growth forecasts for various technological sectors (with an emphasis on sustainable energy), an improved understanding of the underlying research landscape, as well as the identification of influential researchers or research groups. This paper focuses on the development of techniques to both organize and visualize the data in a way which reflects the semantic relationships between keywords. We studied the use of the joint term frequencies of pairs of keywords, as a means of characterizing this semantic relationship – this is based on the intuition that terms which frequently appear together are more likely to be closely related. Some of the results reported herein describe: (1) Using appropriate tools and methods, exploitable patterns and information can certainly be extracted from publicly available databases, (2) Adaptation of the Normalized Google Distance (NGD) formalism can provide measures of keyword distances that facilitate keyword clustering and hierarchical visualization, (3) Further adaptation of the NGD formalism can be used to provide an asymmetric measure of keyword distances to allow the automatic creation of a keyword taxonomy, and (4) Adaptation of the Latent Semantic Approach (LSA) can be used to identify concepts underlying collections of keywords. Wed, 01 Apr 2009 00:00:00 GMT https://hdl.handle.net/1721.1/102838 2009-04-01T00:00:00Z https://hdl.handle.net/1721.1/102837 Reconciliation of temporal semantic heterogeneity in evolving information systems Zhu, Hongwei; Madnick, Stuart E. The change in meaning of data over time poses significant challenges for the use of that data. These challenges exist in the use of an individual data source and are further compounded with the integration of multiple sources. In this paper, we identify three types of temporal semantic heterogeneity. We propose a solution based on extensions to the Context Interchange framework, which has mechanisms for capturing semantics using ontology and temporal context. It also provides a mediation service that automatically reconciles semantic conflicts. We show the feasibility of this approach with a prototype that implements a subset of the proposed extensions. Wed, 01 Apr 2009 00:00:00 GMT https://hdl.handle.net/1721.1/102837 2009-04-01T00:00:00Z https://hdl.handle.net/1721.1/102836 Preventing Accidents and Building a Culture of Safety: Insights from a Simulation Model Lyneis, John; Madnick, Stuart E. Research has approached the topic of safety in organizations from a number of different perspectives. On the one hand, psychological research on safety climate gives evidence for a range of organizational factors that predict safety across organizations. On the other hand, organizational learning theorists view safety as a dynamic problem in which organizations must learn from mistakes. Here, we synthesize these two streams of research by incorporating key organizational factors from the safety climate literature into a dynamic simulation model that also includes the possibility for learning. Analysis of simulation results sheds insight into the nature of reliability and confirms the dangers of over-reliance on ‘single loop learning’ as a mechanism for controlling safety behaviors. Special emphasis is placed on strategies that managers might use to encourage learning and prevent erosion in safety behaviors over time. Wed, 01 Apr 2009 00:00:00 GMT https://hdl.handle.net/1721.1/102836 2009-04-01T00:00:00Z https://hdl.handle.net/1721.1/102835 Does Geographic Clustering Still Benefit High Tech New Ventures? The Case of the Cambridge/Boston Biotech Cluster Allen, Thomas J.; Raz, Ornit; Gloor, Peter A. An empirical study of scientific communication among biotechnology companies supports the belief that geographic clustering does produce increased scientific exchange among companies. A comparison of companies within a constrained geographic area with those more dispersed shows a significantly higher level of scientific communication among the former. Scientific communication declines rapidly with plupical separation. Critical of the formation of cluster – based scientific communication networks is the presence of both universities and large firms from the same industry. Wed, 01 Apr 2009 00:00:00 GMT https://hdl.handle.net/1721.1/102835 2009-04-01T00:00:00Z https://hdl.handle.net/1721.1/102834 Market-based valuation of transmission network expansion. A heuristic application in GB Chamorro, Jose M.; Abadie, Luis M.; de Neufville, Richard; Ilic, Marija Transmission investments are currently needed to meet an increasing electricity demand, to address security of supply concerns, and to reach carbon emissions targets. A key issue when assessing the benefits from an expanded grid concerns the valuation of the uncertain cash flows that result from the expansion. We develop a valuation model which combines optimization techniques, Monte Carlo simulation over the expansion project lifetime, and market data from futures contracts on commodities. The model allows for random failures in generation and transmission infrastructure. Uncertainty stems also from nodal loads, fuel prices, allowance prices, wind generation, and hydro generation. Thus the model accounts for the stochastic dynamics on both the demand side and the supply side. To demonstrate the model by example, we consider a simplified network with two nodes. It is intended to broadly resemble the power generation sectors in England/Wales and Scotland. We then focus on the proposed Western HVDC subsea link. We simulate the whole distribution of effects on system costs, carbon emissions, and unserved load. Thu, 01 Dec 2011 00:00:00 GMT https://hdl.handle.net/1721.1/102834 2011-12-01T00:00:00Z https://hdl.handle.net/1721.1/102833 The Use of Safety Cases in Certification and Regulation Leveson, Nancy G. Certification of safety-critical systems is usually based on evaluation of whether a system or product reduces risk of specific losses to an acceptable level. There are major differences, however, in how that decision is made and on what evidence is required. The term Safety Case has become popular recently as a solution to the problem of regulating safety-critical systems. The term arises from the HSE (Health and Safety Executive) in the U.K., but different definitions seem to be rife. To avoid confusion, this paper uses the term “assurance cases” for the general term and limits the use of the term “safety case” to a very specific definition as an argument for why the system is safe. This paper examines the use of safety cases and regulation in general. The first important distinction is between types of regulation. Tue, 01 Nov 2011 00:00:00 GMT https://hdl.handle.net/1721.1/102833 2011-11-01T00:00:00Z https://hdl.handle.net/1721.1/102832 An approximate dynamic programming framework for modeling global climate policy under decision-dependent uncertainty Webster, Mort; Santen, Nidhi R.; Parpas, Panos Analyses of global climate policy as a sequential decision under uncertainty have been severely restricted by dimensionality and computational burdens. Therefore, they have limited the number of decision stages, discrete actions, or number and type of uncertainties considered. In particular, other formulations have difficulty modeling endogenous or decision-dependent uncertainties, in which the shock at time t+1 depends on the decision made at time t. In this paper, we present a stochastic dynamic programming formulation of the Dynamic Integrated Model of Climate and the Economy (DICE), and the application of approximate dynamic programming techniques to numerically solve for the optimal policy under uncertain and decision-dependent technological change. We compare numerical results using two alternative value function approximation approaches, one parametric and one non-parametric. Using the framework of dynamic programming, we show that an additional benefit to near-term emissions reductions comes from a probabilistic lowering of the costs of emissions reductions in future stages, which increases the optimal level of near-term actions. Thu, 01 Sep 2011 00:00:00 GMT https://hdl.handle.net/1721.1/102832 2011-09-01T00:00:00Z https://hdl.handle.net/1721.1/102831 An approximate dynamic programming approach for designing train timetables Pena Alcaraz, Maite; Webster, Mort; Ramos, Andres Traditional approaches to solving the train timetabling problem—the optimal allocation of when each train arrives and departs each station—have relied on Mixed-Integer Programming (MIP) approaches. We propose an alternative formulation for this problem based on the modeling and algorithmic framework of approximate dynamic programming. We present a Q-learning algorithm in order to tractably solve the high-dimensional problem. We compare the performance of several variants of this approach, including discretizing the state and the action spaces, and continuous function approximation with global basis functions. We demonstrate the algorithms on two railway system cases, one minimizing energy consumption subject to punctuality constraints, and one maximizing capacity subject to safety constraints. We demonstrate that the ADP algorithm converges rapidly to an optimal solution, and that the number of iterations required increases linearly in the size of the rail system, in contrast with MIP approaches whose computation time grows exponentially. We also show that an additional benefit to the ADP approach is the intuition gained from visualizing the Q-factor functions, which graphically capture the intuitive tradeoffs between efficiency and constraints in both examples. Mon, 01 Aug 2011 00:00:00 GMT https://hdl.handle.net/1721.1/102831 2011-08-01T00:00:00Z https://hdl.handle.net/1721.1/102830 Growth Patterns of Subway/Metro Systems Tracked by Degree Correlation Whitney, Daniel E. Urban transportation systems grow over time as city populations grow and move and their transportation needs evolve. Typical network growth models, such as preferential attachment, grow the network node by node whereas rail systems grow by adding entire lines with all their nodes. The objective of this paper is to see if any canonical regular network forms capture the growth patterns of urban metro systems for which we have historical data in terms of old maps. Data from these maps reveal that the systems’ Pearson degree correlation grows increasingly toward positive values over time and in some cases becomes decidedly positive. We have derived closed form expressions for degree correlation and clustering coefficient for a variety of canonical forms that might be similar to metro systems. Of all those examined, only a few types patterned after a wide area network (WAN) with a “core-periphery” structure show similar behavior of the degree correlation as network size increases. This suggests that large metro systems either are designed or evolve into the equivalent of message carriers that seek to balance travel between arbitrary node-destination pairs with avoidance of congestion in the central regions of the network. Mon, 01 Aug 2011 00:00:00 GMT https://hdl.handle.net/1721.1/102830 2011-08-01T00:00:00Z https://hdl.handle.net/1721.1/102829 Financing Methods for High-Speed Rail with Application to Portugal Huang, Teng; Sussman, Joseph M. High-Speed Rail (HSR) is of substantial and growing interest around the world. The European Union (EU) sees it as an integrating force; China is investing at an extraordinary level and even the U.S. is trying to move forward. Although HSR is expected to shrink the temporal distance between cities, reshape the travel patterns of people toward—we hope—environmentally-friendly ones, create an image effect for the country building it, promote regional economics, etc., HSR is an expensive alternative. It is more capital intensive than other transportation projects in both unit cost (the cost per lane or track km) and total cost. On the other hand, HSR can aid in the formations of megaregions with the potential for economic growth. This paper discusses the cost characteristics of HSR, analyzes HSR’s potential economic influence on megaregions, and identifies megaregion-related revenues that can make HSR more financially viable: specifically, we discuss the use of value capture mechanisms to capture the megaregion economic benefits of HSR in order to finance such systems. Mon, 01 Aug 2011 00:00:00 GMT https://hdl.handle.net/1721.1/102829 2011-08-01T00:00:00Z https://hdl.handle.net/1721.1/102828 ESD Summer Reading Lists 2003–2011 Sussman, Joseph M. Back in 2003, when ESD was a toddler of about 41⁄2, we were preparing for our spring semester offsite traditionally held at the end of the academic year in late May or early June. I had the idea of preparing a short list of books with relevance to the ESD mission—the study of complex sociotechnical systems—and presented that idea to the then (and founding) ESD director Prof. Daniel Roos. He agreed it would be worthwhile as an experiment, and so I did create the first ESD Summer Faculty Reading List. A “summer” reading list carries the suggestion of books you can take to “the beach”. So no “text books” were included. The books were treatments of critical contemporary issues that the world faces, important methods and perspectives germane to these issues and the complex sociotechnical systems in general, and relevant history. In retrospect, the beach would likely be too distracting a venue for many of these books! Fri, 01 Jul 2011 00:00:00 GMT https://hdl.handle.net/1721.1/102828 2011-07-01T00:00:00Z https://hdl.handle.net/1721.1/102827 Concepts in Uncertainty—Four brief teaching notes Sussman, Joseph M. In Spring 2010 I taught—for the first time—an undergraduate required subject in project evaluation (1.011). In the course of that teaching, I wrote and distributed several teaching notes, which were intended to illustrate for the student various systems concepts. The ones included here focused on the theme of uncertainty and how one deals with it. The first two teaching notes deal with uncertainly in weather prediction and other natural phenomena. The first built on a “snowstorm that never happened” in Boston, as dire forecasts for snow were not indeed realized in February 2010. The paper tries to explain why this kind of thing can happen, given the relationship between storm tracks and amounts of fallen snow at a particular site. The second deals with tsunamis and the state-of-the-art in prediction of tsunamis, which occur as a result of earthquakes. This was motivated by an earthquake that took place in Chile, which many were concerned would lead to tsunamis across the Pacific, with dire effects on islands such as Guam and potentially even Japan. Here big tsunamis were predicted but didn’t occur. Again, we used that example to highlight uncertainties and why errors of this sort were made. The third and fourth teaching notes deal with professional American football and decision-making under uncertainty. I tried to write these so that one didn’t have to be expert in the rules of football to follow the argument. In November 2009, New England Patriots coach Bill Belichick, made a quite controversial decision trying to convert a first down on a fourth down play in the last two minutes of a game with the Indianapolis Colts. The Patriots were leading at the time and a successful first down would have allowed the Patriots to retain possession of the ball, guaranteeing a win. His gamble failed; the Patriots did not make the first down and so surrendered the ball, and ultimately lost the game. So the third teaching note tried to explain why Belichick—widely hailed as one of the best coaches in NFL football history—could have made such a “blunder.” The fourth teaching note was a follow up and was concerned with the concept of rationality. Economists use the “rational actor” model to “predict” what people will do when faced with various choices. Often the economists are wrong in their predictions because their definition of rationality may well differ from that of the people actually making the decisions. We illustrate that by considering metrics other than simply maximizing the probability of winning the football game, as in teaching note 3. We included an “embarrassment factor,” which reflects some football coaches concern with appearing foolish when they make a gamble that fails. So they may make an “irrational” decision in the eyes of some, because they are not maximizing their team’s chance to win, but also include in their calculation how embarrassed they might be by their decision, which the coach sees as entirely rational. These teaching notes would be of interest to the reader who is concerned with teaching uncertainty concepts to undergraduates, and may be of value to those who teach introductory graduate classes as well. Any comments on the substance, content, clarity, and value of the approach would be greatly appreciated. Fri, 01 Jul 2011 00:00:00 GMT https://hdl.handle.net/1721.1/102827 2011-07-01T00:00:00Z https://hdl.handle.net/1721.1/102826 After Action Reports: Lessons on Vaccine Distribution Hopkins, Julia The responses of individual states to the 2009 H1N1 Pandemic are documented in their After Action Reports (AARs), written in summer 2010. In an attempt to understand how these responses could improve for future pandemics, this paper reviews the AARs of fourteen states to determine how vaccine distribution methods and communication issues impacted the success of the states’ responses to the 2009 H1N1 Pandemic. The results of this review reveal several trends to inform preparation for future pandemics. For instance, the best distribution method for times of low supply of vaccine and high demand is one based on county populations within a state, while an online ordering system for vaccine performs well in times of high supply and lower demand. Finally, this paper finds that the best preparedness plans are the ones for which components have been tested in some capacity prior to use. Wed, 01 Jun 2011 00:00:00 GMT https://hdl.handle.net/1721.1/102826 2011-06-01T00:00:00Z https://hdl.handle.net/1721.1/102825 Introducing Complex Sociotechnical Systems to First-and Second-Year Students Siddiqi, Afreen; Clewlow, Regina; Sussman, Joseph M. Retention of undergraduate engineering students remains a key challenge faced across the globe; in particular, the first two years of the required curriculum is often cited as a significant hurdle. Many students are attracted to engineering in order to solve important real-world problems. However, in the first two years, the majority of students find themselves in classes focused on the fundamentals of math and science, with little or no apparent connection to the real-world issues they care deeply about. Furthermore, most students traditionally develop a deep understanding in a specific engineering discipline, with limited opportunity to consider or analyze complex, sociotechnical systems (e.g. energy systems, transportation networks, healthcare) – systems that are the focus of critical engineering challenges. Although the subject of large-scale, sociotechnical systems has been successfully integrated into the realm of graduate education, it has seen limited attention in undergraduate studies where it has the potential to inspire and help retain the next generation of engineers. This paper describes the development and implementation of a novel course, intended for freshmen and sophomores, that has been designed to address some of the needs of a new generation of students who are passionate and more engaged than ever before in understanding and impacting contemporary problems. The new course centers around the theme of Critical Contemporary Issues (CCI) – important and difficult problems pertinent to our present times on topics of sustainability, mobility, energy and the environment, healthcare, communication, the internet etc. In this course, we weave introductory instruction in system dynamics, networks and uncertainty with teams working on different semester-long projects. Through this approach, we enable students to engage in and understand the issues at play in a problem of their interest, appreciate the scope of the sociotechnical complexities in CCIs, and gain an introduction to analytical tools that can help in addressing some of these issues. This paper discusses the overall philosophy and motivation for establishing the course, the design of the curriculum, and the approach, execution, and integration of team-based projects. Sun, 01 May 2011 00:00:00 GMT https://hdl.handle.net/1721.1/102825 2011-05-01T00:00:00Z https://hdl.handle.net/1721.1/102824 Feature Performance Metrics for Software as a Service Offering: The Case of HubSpot Latner, Avi; Valerdi, Ricardo This paper provides an industry case study for measuring the performance of software as a service (SaaS) product features in order to prioritize development efforts. The case is based on empirical data from HubSpot and it is generalized to provide a framework applicable to other companies with large scale software offerings and distributed development. Firstly, relative value is measured by the impact that each feature has on customer acquisition and retention. Secondly, feature value is compared to feature cost and specifically development investment to determine feature profitability. Thirdly, feature sensitivity is measured. Feature sensitivity is defined as the effect a fixed amount of development investment has on value in a given time. Fourthly, features are segmented according to their location relative to the value to cost trend line into: most valuable features, outperforming, underperforming and fledglings. Finally, results are analyzed to determine future action. Maintenance and bug fixes are prioritized according to feature value. Product enhancements are prioritized according to sensitivity with special attention to fledglings. Underperforming features are either put on “lifesupport”, terminated or overhauled. Tue, 01 Mar 2011 00:00:00 GMT https://hdl.handle.net/1721.1/102824 2011-03-01T00:00:00Z https://hdl.handle.net/1721.1/102823 Framing the Climate Debate: Knowledge Affirmation vs. Risk Mitigation Waugh, Caleb Joseph Opinions regarding the anthropogenic climate change hypothesis (ACC), along with the possibility of subsequent catastrophic environmental impacts, often break down along ideological lines that have lead to a dichotomy between “believers” on the one hand, and “non-believers” on the other. Although some scientific uncertainty remains, the current body of scientific evidence supporting the hypothesis is significant and enough to warrant consideration of a strong policy response. However, for any progress to be made on the policy front, the existing ideological dichotomy between believers/non-believers must be overcome. This will require policy advocates, including scientists, to do a much better job framing the scientific argument for policy intervention more in terms of the inherent scientific uncertainty and risk mitigation instead of suggesting that scientific outcomes and subsequent catastrophic events are indisputable. Much can be learned regarding a proper framing of climate science through philosophical reflection of the metaphysical and epistemological nature of science, and by considering similar historical examples of scientific knowledge assessment. Although reframing the debate in terms of the inherent scientific uncertainty is not sufficient to overcome all obstacles, having policy makers and the general public at large properly recognizing the nature of the scientific argument, instead of adhering to a believer/non-believer false dichotomy, is a first and necessary step. Tue, 01 Mar 2011 00:00:00 GMT https://hdl.handle.net/1721.1/102823 2011-03-01T00:00:00Z https://hdl.handle.net/1721.1/102822 The Portuguese High Speed Rail Network; Relating Financing to Strategic and Operating Issues de Abreu e Silva, Joao; Silva, Duarte; Sussman, Joseph M. This paper describes the implementation of the Portuguese High Speed Rail (HSR) Network. The business model developed by RAVE for the PPP’s related with the HSR infrastructure is described and discussed. Following a recently awarded research project (EXPRESS) aimed at studying the strategic aspects related with the implementation of HSR is presented and its aspects more directly related with HSR operation which could be relevant in a PPP context are discussed. Sat, 01 Jan 2011 00:00:00 GMT https://hdl.handle.net/1721.1/102822 2011-01-01T00:00:00Z https://hdl.handle.net/1721.1/102821 The Dynamics of Circular Migration in Southern Europe: An Example of Social Innovation Maranon-Abreu, Rafael; Caballero, Estrella Gualda; Valerdi, Ricardo During economic crises, governments establish policies that facilitate the creation of jobs, goods and services that make their economies more resilient. Often, this requires innovative social programs that match global migratory trends to local labor demand. The implementation of such programs requires a significant degree of innovation that requires models that can capture the complexity involved. To explore this phenomenon, we provide a multi-disciplinary view of innovative social programs that shed light on the dynamic characteristics of the political, social, technological and economic aspects of circular migration. Our focus is a case study of the European Union-funded circular migration program to support the strawberry harvest in the province of Huelva in Spain. Covering the time period of 1999-2011, this paper provides a system dynamics model to represent the key elements that led to the success of circular migration from the standpoint of economic and social change. The model helps explain the key factors that make the program robust under recent economic crisis conditions. Based on a qualitative analytical approach, the model demonstrates how adaptive policies can enable macroeconomic equilibrium in environments where circular migration can be implemented. We also show that circular migration is not an impediment to economic recovery, in fact, it helps stabilize the labor supply in times of high uncertainty. Sat, 01 Jan 2011 00:00:00 GMT https://hdl.handle.net/1721.1/102821 2011-01-01T00:00:00Z https://hdl.handle.net/1721.1/102820 Price of Airline Frequency Competition Vaze, Vikrant; Barnhart, Cynthia Frequency competition influences capacity allocation decisions in airline markets and has important implications to airline profitability and airport congestion. Market share of a competing airline is a function of its frequency share and the relationship between the two is pivotal for understanding the impacts of frequency competition on airline business. Based on the most commonly accepted form of this relationship, we propose a game-theoretic model of airline frequency competition. We characterize the conditions for existence and uniqueness of a Nash equilibrium for the 2-player case. We analyze two different myopic learning dynamics for the non-equilibrium situations and prove their convergence to Nash equilibrium under mild conditions. For the N-player game between identical players, we characterize all the pure strategy equilibria and identify the worst-case equilibrium, i.e. the equilibrium with maximum total cost. We provide an expression for the measure of inefficiency, similar to the price of anarchy, which is the ratio of the total cost of the worst-case equilibrium to the total cost of the cost minimizing solution and investigate its dependence on different parameters of the game. Wed, 01 Dec 2010 00:00:00 GMT https://hdl.handle.net/1721.1/102820 2010-12-01T00:00:00Z https://hdl.handle.net/1721.1/102819 Comparative Study of High-Speed Passenger Rail Deployment in Megaregion Corridors: Current Experiences and Future Opportunities Melibaeva, Sevara; Sussman, Joseph M.; Dunn, Travis Deployment of high-speed passenger rail services has occurred around the world in densely-populated corridors, often with the effect of either creating or enhancing a unified economic “megaregion” agglomeration. This paper will review the technical characteristics of a variety of megaregion corridors, including Japan (Tokyo-Osaka), France (Paris-Lyon), and Germany (Frankfurt-Cologne), and their economic impacts. There are many lessons to be drawn from the deployment and ongoing operation of high-speed passenger rail service in these corridors for other countries now considering similar projects, such as the US and parts of the European Union. First, we review three international cases, describing the physical development of each corridor as well as its measured impacts on economic development. In each case, the travel time reductions of the high-speed service transformed the economic boundaries of the urban agglomerations, integrating labor and consumer markets, while often simultaneously raising concerns about the balance of growth within the region. Next, we examine the implications of these international experiences for high-speed rail deployment elsewhere in the world, particularly the US and Portugal. Issues considered include the suitability of high-speed passenger rail service in existing megaregions as well as the potential for formation of megaregions in other corridors. By understanding the impact of high-speed passenger service on economic growth, labor markets, urban form, and the regional distribution of economic activity, planners can better anticipate and prepare countermeasures for any negative effects of high-speed rail. Wed, 01 Dec 2010 00:00:00 GMT https://hdl.handle.net/1721.1/102819 2010-12-01T00:00:00Z https://hdl.handle.net/1721.1/102818 Valuing the Commons: A Fundamental Challenge across Complex Systems Cutcher-Gershenfeld, Joel; Lawson, Chris The political, economic and social landscapes of the 21st Century are increasingly dominated by complex, sociotechnical systems that are essential to human civilization, yet incompletely addressed with existing theory, tools, methods, and policies. Illustrative systems are found in transportation, information, finance, energy, health care, education, disaster response, and supply chains. Social, behavioral and economic sciences in the 20th Century were focused on hierarchical corporations and expanding markets – the organizational and institutional underpinnings of the industrial revolution. Twentieth Century successes were tempered by various “tragedies of the commons” (such as negative impacts on working conditions, human dignity, the environment, and developing economies). In the 21st Century, increasing interdependencies and accelerating rates of change are dramatically expanding the ways in which complex “systems” shape organizations and markets. Multi-level research incorporating the systems context and systems-level policies have great transformative potential – addressing externalities and expanding how we “value the commons.” This white paper highlights layers and networks of aligned (or misaligned) stakeholders, which are at the heart of these systems. Orienting social, behavioral, and economic sciences and public polices to better address stakeholders in complex systems is essential to generating new forms of value for society and mitigating catastrophic systems failures. Mon, 01 Nov 2010 00:00:00 GMT https://hdl.handle.net/1721.1/102818 2010-11-01T00:00:00Z https://hdl.handle.net/1721.1/102817 Literature Review of Papers relevant to the topic of development impacts and economic evaluation methods of High-Speed Rail (HSR) Radopoulou, Stefania; Melibaeva, Sevara; Huang, Teng; Sussman, Joseph M. With HSR continuing to the target of investments around the world, with even the United States elevating the place of HSR on the public agenda, we thought this compendium of summaries of references on HSR and related topics would be of value. We begin with references on transportation investment and economic development in general. Then we consider the case of HSR and economic development on the local and urban as well as the national regional levels, Some references on economic geography and disparities among regions are included. We conclude with references for demand forecasting and some general references in the HSR field. Mon, 01 Aug 2011 00:00:00 GMT https://hdl.handle.net/1721.1/102817 2011-08-01T00:00:00Z https://hdl.handle.net/1721.1/102816 A Teaching Note on “Real Options” Sussman, Joseph M. The engineering life is uncertain. We often need to make decisions now that we hope will be effective some years from now. One approach to this conundrum is to design “flexibility” into our projects, hedging against future uncertainties. This sounds reasonable and it is, but it is not “free”. Including flexibility is our design can be costly and if it turns out not to be needed in the future, it is money down the drain. So how do we know when to design in flexibility and when not to? Intuitively, the more uncertain we are about the future, the more the chances are that we will need flexibility. “Real Options Analysis” (ROA) is a method we can use to put a value on flexibility and decide whether or not we should spend the resources now to hedge against future uncertainties. This teaching note, prepared for an undergraduate class at MIT, is an approach developed by the author, to explicate these concepts. Wed, 01 Sep 2010 00:00:00 GMT https://hdl.handle.net/1721.1/102816 2010-09-01T00:00:00Z https://hdl.handle.net/1721.1/102815 Towards An Integration Of The Lean Enterprise System, Total Quality Management, Six Sigma And Related Enterprise Process Improvement Methods Bozdogan, Kirkor The lean enterprise system, total quality management, six sigma, theory of constraints, agile manufacturing, and business process reengineering have been introduced as universally applicable best methods to improve the performance of enterprise operations through continuous process improvement and systemic planned enterprise change. Generally speaking, they represent practice-based, rather than theory-grounded, methods with common roots in manufacturing. Most of the literature on them is descriptive and prescriptive, aimed largely at a practitioner audience. Despite certain differences among them, they potentially complement each other in important ways. The lean enterprise system, total quality management and six sigma, in particular, are tightly interconnected as highly complementary approaches and can be brought together to define a first-approximation “core” integrated management system, with the lean enterprise system serving as the central organizing framework. Specific elements of the other approaches can be selectively incorporated into the “core” enterprise system to enrich its effectiveness. Concrete theoretical and computational developments in the future through an interdisciplinary research agenda centered on the design and development of networked enterprises as complex adaptive socio-technical systems, as well as the creation of a readily accessible observatory of evidence-based management practices, would represent important steps forward. Sun, 01 Aug 2010 00:00:00 GMT https://hdl.handle.net/1721.1/102815 2010-08-01T00:00:00Z https://hdl.handle.net/1721.1/102814 Evolution Of The Lean Enterprise System: A Critical Synthesis And Agenda For The Future Bozdogan, Kirkor Many aerospace enterprises and other organizations have adopted a variety of management approaches to achieve continuous process improvement, enterprise change and transformation, such as the lean enterprise system, total quality management (TQM), theory of constraints (TOC), agile manufacturing, and business process reengineering (BPR). Among them, the lean enterprise system, with its origins in the Toyota Production System (TPS), comes closest to providing a holistic view of enterprises as complex socio-technical systems embodying a mutually supportive set of precepts and practices driving enterprise operations at all levels (i.e., strategic, tactical, operational) and throughout the enterprise value stream encompassing both upstream supplier networks and downstream customer focused activities. Lean enterprise principles and practices have evolved over many decades through a process of experimentation, learning and adaptation. A distinction is made between the basic lean enterprise system (BLES), capturing salient developments over the period between the late 1940s and mid-1990s, and the contemporary lean enterprise system (CLES), capturing major conceptual and implementation-related extensions of the basic model since the mid-1990s. The lean enterprise system, as a viable framework for explaining the structure and dynamics of modern networked enterprises, for managing them, and for improving their performance through either continuous process improvement or planned systemic change and transformation, remains a work-in-progress. Sun, 01 Aug 2010 00:00:00 GMT https://hdl.handle.net/1721.1/102814 2010-08-01T00:00:00Z https://hdl.handle.net/1721.1/102813 Simulating the Impact of Strategy Development Frameworks on Transportation Infrastructure System Performance Dunn, Travis P.; Sussman, Joseph M. This paper develops, through a simulation model, a deeper understanding of the relationship between transportation infrastructure strategy development frameworks and system performance. A strategy development framework for transportation can be characterized by the infrastructure ownership structures, cross-modal and cross-sectoral linkages, revenue sources, resource allocation decision-making processes, and geographic scales of the organizations responsible for making infrastructure investments. Taking the dimensions of a strategy development framework as inputs, the model simulates investments in an infrastructure network over time—in this paper, the national intercity roadway network of Portugal. The results demonstrate the value of using simulation models of complex transportation systems to inform the decisions of not only planners but also of stakeholders who design strategy development frameworks. Such a tool is particularly important given the ongoing reorganizations of the Portuguese transportation sector, including increasing reliance on concession agreements, highway tolls, and sub-national government participation. Sun, 01 Aug 2010 00:00:00 GMT https://hdl.handle.net/1721.1/102813 2010-08-01T00:00:00Z https://hdl.handle.net/1721.1/102812 Teaching about Complex Sociotechnical Systems (CSS) Sussman, Joseph M. Prof Chris Magee and I teach the doctoral seminar in engineering systems (ESD.83) required for all ESD doctoral students usually in the first semester they are registered as doctoral students. One of the assignments deals with students characterizing a complex sociotechnical system (CSS) of interest to them along various dimensions. For this assignment we provide them with the following paper: Complex, Sociotechnical Systems (CSS): Some Fundamental Concepts and ask the students to use the framework provided by the paper to do their characterizations. I thought this short paper (and the assignment) would be of interested to faculty teaching other comparable courses in various programs in engineering, management, systems engineering, social science, and so forth. We include the assignment itself as an appendix to the paper. Comments are more than welcome. I emphasize this is not intended as a research paper but more a teaching note to help students structure their thinking in a consistent manner. Thu, 01 Jul 2010 00:00:00 GMT https://hdl.handle.net/1721.1/102812 2010-07-01T00:00:00Z https://hdl.handle.net/1721.1/102811 Detecting Evolving Patterns of Self-Organizing Networks by Flow Hierarchy Measurement Luo, Jianxi; Magee, Christopher L. Hierarchies occur widely in evolving self-organizing ecological, biological, technological and social networks, but detecting and comparing hierarchies is difficult. Here we present a metric and technique to quantitatively assess the extent to which self-organizing directed networks exhibit a flow hierarchy. Flow hierarchy is a commonly observed but theoretically overlooked form of hierarchy in networks. We show that the ecological, neurobiological, economic and information processing networks are generally more hierarchical than their comparable random networks. We further discovered that hierarchy degree has increased over the course of the evolution of Linux kernels, confirming an early hypothesis by Herbert Simon on the emergence of hierarchy in evolutionary processes. Taken together, our results suggest that hierarchy is a central organizing feature of real-world evolving networks, and the measurement of hierarchy opens the way to understand the structural regimes and evolutionary patterns of self-organizing networks. Our measurement technique makes it possible to objectively compare hierarchies of different networks and of different evolutionary stages of a single network, and compare evolving patterns of different networks. It can be applied to various complex systems, which can be represented as directed networks. Tue, 01 Jun 2010 00:00:00 GMT https://hdl.handle.net/1721.1/102811 2010-06-01T00:00:00Z https://hdl.handle.net/1721.1/102810 Strategies to Overcome Network Congestion in Infrastructure Systems Black, Jason W.; Larson, Richard Charles Networked Infrastructure systems deliver services and/or products from point to point along the network. They include transportation networks (e.g., rails, highways, airports, sea ports), telecommunication networks (by frequency-bounded airwaves or cables), and utilities (e.g., electric power, water, gas, oil, sewage). Each is a fixed capacity system having marked time-of-day and day-of-week patterns of demand. Usually, the statistics of demand, including hourly patterns (i.e., means and variances) are well known and often correlated with outside factors such as weather (short term) and the general economy (longer term). Wed, 01 Nov 2006 00:00:00 GMT https://hdl.handle.net/1721.1/102810 2006-11-01T00:00:00Z https://hdl.handle.net/1721.1/102809 Offshoring: The Transition From Economic Drivers Toward Strategic Global Partnership and 24-Hour Knowledge Factory Gupta, Amar; Seshasai, Satwik; Mukherji, Sourav; Ganguly, Auroop The concept of offshoring of professional services first gained attention slightly over 25 years ago. At that time, US companies began to realize the cost-advantage of getting their computer software developed in India and other countries. The concept gained momentum with the advent of Internet and the availability of inexpensive communication technologies. Unrelated events, such as the need to address the Y2K problem, in a timebound manner, further increased the use of computer personnel based in faraway places. Studies conducted by professional organizations, such as ACM, IEEE, and NSPE, focus on the cost and labor aspects of offshoring and its direct impact on employment opportunities in the countries involved. This paper broadens this perspective by emphasizing that the key drivers for offshoring will be strategic, not economic, over time. A formal mathematical model is presented to highlight the new trend. Further, instead of a binary model in which the work is performed in the country of the sponsoring organization or a different country, we will gradually see a new work paradigm in which the work is performed in a sequence in factories located in multiple continents of the world. Such 24-Hour Knowledge Factories can leverage factors beyond cost savings. One can employ professionals in multiple parts of the world, perform tasks at all times of the day, and bring new products and services quicker to the market. Just as the advent of multiple shifts allowed machines to be utilized round the clock leading to the benefits of the Industrial Revolution, the creation of new globally distributed workforces and global partnerships can lead to major strategic advantages for companies and countries alike. Wed, 01 Nov 2006 00:00:00 GMT https://hdl.handle.net/1721.1/102809 2006-11-01T00:00:00Z https://hdl.handle.net/1721.1/102808 Decision-Making in the Political and Technical Environments Broniatowski, David Andre; Wiegel, Annalisa L. Mutual misunderstanding between decision-makers in the political and technical environment leads to programs that experience cost overruns, schedule delays and, often, cancellation. This paper compares and contrasts the determinants of decision-making in the technical and political realms, with the intention of demonstrating how these decisions translate to cost, schedule and performance parameters. Studies of those elements that are most salient to the policy maker are informed by the political science literature. In particular, studies of administrative, bureaucratic and Congressional decision-making are instructive in determining how an engineering system interacts with the political realm. So as to lend concreteness to this analysis, we focus on NASA’s interactions with Congress surrounding the Vision for Space Exploration, announced by President Bush on January 14th, 2004. Sun, 01 Oct 2006 00:00:00 GMT https://hdl.handle.net/1721.1/102808 2006-10-01T00:00:00Z https://hdl.handle.net/1721.1/102807 Bulk Power Grid Risk Analysis: Ranking Infrastructure Elements According to their Risk Significance Koonce, A. M.; Apostolakis, George; Cook, B. K. Disruptions in the bulk power grid can result in very diverse consequences that include economic, social, physical, and psychological impacts. In addition, power outages do not affect all end-users of the system in the same manner. For these reasons, a risk analysis of bulk power systems requires more than determining the likelihood and magnitude of power outages; it must also include the diverse impacts power outages have on the users of the system. We propose a methodology for performing a risk analysis on the bulk power system. A power flow simulation model is used to determine the likelihood and extent of power outages when components within the system fail to perform their designed function. The consequences associated with these failures are determined by looking at the type and number of customers affected. Stakeholder input is used to evaluate the relative importance of these consequences. The methodology culminates with a ranking of each system component by its risk significance to the stakeholders. The analysis is performed for failures of infrastructure elements due to both random causes and malevolent acts. Fri, 01 Sep 2006 00:00:00 GMT https://hdl.handle.net/1721.1/102807 2006-09-01T00:00:00Z https://hdl.handle.net/1721.1/102806 House of Security: Locale, Roles and Resources for Ensuring Information Security Research-in-Progress Ang, Wee Horng; Lee, Yang W.; Madnick, Stuart E.; Mistress, Dinsha; Siegel, Michael D.; Strong, Diane M.; Wang, Richard Y.; Yao, Chrisy In this paper we redefine information security by extending its definition in three salient avenues: locale (beyond the boundary of an enterprise to include partner organizations), role (beyond the information custodians’ view to include information consumers’ and managers’ views), and resource (beyond technical dimensions to include managerial dimensions). Based on our definition, we develop a model of information security, which we call the House of Security. This model has eight constructs, Vulnerability, Accessibility, Confidentiality, IT Resources for Security, Financial Resources for Security, Business Strategy for Security, Security Policy and Procedures, and Security Culture. We have developed a questionnaire to measure the assessment and importance of information security along these eight aspects. The questionnaire covers multiple locales and questionnaire respondents cover multiple roles. Data collection is currently in process. Results from our analysis of the collected data will be ready for presentation at the conference. Tue, 01 Aug 2006 00:00:00 GMT https://hdl.handle.net/1721.1/102806 2006-08-01T00:00:00Z https://hdl.handle.net/1721.1/102805 Reutilization and Legal Protection of Non-Copyrightable Database Contents Zhu, Hongwei; Madnick, Stuart E. The availability of data on the web and the improvement of technologies have made it increasingly easy to reuse existing data to create new databases and provide value-added services. Meanwhile, initial database creators have been seeking legal protection for their data. After presenting a brief history of legislation related to legal protection for non-copyrightable database contents, we discuss challenging issues to be considered in formulating a database protection regulation. These issues can be addressed from the perspective of economics. Results from a preliminary economic analysis are presented. The findings indicate that depending on investment required to create the initial database and the level of differentiation between the initial database and the reuser database, the choice of a social welfare-enhancing regulation can allow for no reuse, free reuse, or fee-paying reuse. Tue, 01 Aug 2006 00:00:00 GMT https://hdl.handle.net/1721.1/102805 2006-08-01T00:00:00Z https://hdl.handle.net/1721.1/102804 Global Outsourcing of Professional Services Seshasai, Satwik As a growing number of firms outsource more of their professional services across geographic and temporal boundaries, one is faced with a corresponding need to examine the long-term ramifications on business and society. Some persons are convinced that cost considerations should reign as the predominant decision-making factor; others argue that outsourcing means permanent job loss; and still others believe outsourcing makes US goods and services more competitive in the global marketplace. We assert that if outsourcing options need to be analyzed in detail with critical objectivity in order to derive benefits for the concerned constituencies. Tue, 01 Aug 2006 00:00:00 GMT https://hdl.handle.net/1721.1/102804 2006-08-01T00:00:00Z https://hdl.handle.net/1721.1/102803 Toward the 24-Hour Knowledge Factory in Software Development Seshasai, Satwik “The Sun never sets on the British Empire,” was a notion emphasized during the eighteenth and nineteenth centuries to highlight that the British Empire was far-flung, and that the sun was always visible from some part of this vast empire. While the British Empire has gradually disintegrated, we can now coin an equivalent notion: “The Sun never sets on the 24-hour Knowledge Factory!” Tue, 01 Aug 2006 00:00:00 GMT https://hdl.handle.net/1721.1/102803 2006-08-01T00:00:00Z https://hdl.handle.net/1721.1/102802 Toward the 24-Hour Knowledge Factory Gupta, Amar; Seshasai, Satwik The term “24-Hour Knowledge Factory” connotes a globally distributed work environment in which members of the global team work on a project around the clock; each member of the team works the normal workday hours that pertain to his or her time zone. At the end of such a workday, a fellow team member located in a different time zone continues the same task. This creates the shift-style workforce that was originally conceived in the manufacturing sector. A globally distributed 24-hour call center is the simplest manifestation of this paradigm. The true example of the 24-hour factory paradigm discussed in this paper involves groups working together to accomplish a given set of deliverables, such as a software project, and transcending conventional spatial and temporal boundaries. Tue, 01 Aug 2006 00:00:00 GMT https://hdl.handle.net/1721.1/102802 2006-08-01T00:00:00Z https://hdl.handle.net/1721.1/102801 Promoting the Concept of Sustainable Transportation within the Federal System - The Need to Reinvent the U.S. DOT Hall, Ralph P.; Sussman, Joseph M. This paper argues that a major obstacle to progress towards sustainable development/transportation is the lack of an integrated approach to decision-making within the U.S. federal system. To address this problem, the concept of sustainable transportation is first broadened to include the transportation sector’s interconnections with other sectors. This revised notion of sustainable transportation is then used to help visualize the need for horizontal integration and co-optimization of policies/regulations/initiatives across federal agencies. From the assumption that a national strategy for sustainable development will remain illusive in the short-term, a ‘U.S. DOT reinvention model’ is endorsed as a useful mechanism to promote sustainable development/transportation policy in the U.S. Tue, 01 Aug 2006 00:00:00 GMT https://hdl.handle.net/1721.1/102801 2006-08-01T00:00:00Z https://hdl.handle.net/1721.1/102800 Trade-off/Positional Analysis (with a Rawlsian Approach to Equity) as an Alternative to Cost-Benefit Analysis (CBA) in Socio-technical Decisions Hall, Ralph P.; Ashford, Nicholas A. This paper introduces a hybrid trade-off/positional analysis framework as an alternative to cost-benefit analysis (CBA). As a decision-support tool, the proposed framework [1] allows decision-makers not to monetize or aggregate non-monetary factors over time; [2] invites the entrance of stakeholders into the debate since there is greater transparency as to who benefits and who is harmed by a particular policy/program/project; [3] enables analysts to undertake a comparative analysis of alternatives over time; and [4] takes into account the important role of technological change in shaping the state and performance of a system. In addition, a Rawlsian approach to incorporating equity into decision-making is advocated. Tue, 01 Aug 2006 00:00:00 GMT https://hdl.handle.net/1721.1/102800 2006-08-01T00:00:00Z https://hdl.handle.net/1721.1/102799 Advances in Supply Chain Management: Potential to Improve Forecasting Accuracy Datta, Shoumen Palit Austin; Granger, Clive W. J. Forecasting is a necessity almost in any operation. However, the tools of forecasting are still primitive in view of the great strides made by research and the increasing abundance of data made possible by automatic identification technologies, such as, radio frequency identification (RFID). The relationship of various parameters that may change and impact decisions are so abundant that any credible attempt to drive meaningful associations are in demand to deliver the value from acquired data. This paper proposes some modifications to adapt an advanced forecasting technique (GARCH) with the aim to develop it as a decision support tool applicable to a wide variety of operations including supply chain management. We have made an attempt to coalesce a few different ideas toward a “solutions” approach aimed to model volatility and in the process, perhaps, better manage risk. It is possible that industry, governments, corporations, businesses, security organizations, consulting firms and academics with deep knowledge in one or more fields, may spend the next few decades striving to synthesize one or more models of effective modus operandi to combine these ideas with other emerging concepts, tools, technologies and standards to collectively better understand, analyze and respond to uncertainty. However, the inclination to reject deep rooted ideas based on inconclusive results from pilot projects is a detrimental trend and begs to ask the question whether one can aspire to build an elephant using mouse as a model. Fri, 01 Jul 2016 00:00:00 GMT https://hdl.handle.net/1721.1/102799 2016-07-01T00:00:00Z https://hdl.handle.net/1721.1/102798 Advances in Supply Chain Management Decision Support Systems: Potential for Improving Decision Support Catalysed by Semantic Interoperability between Systems Datta, Shoumen Palit Austin Globalization has catapulted ‘cycle time’ as a key indicator of operational efficiency [1] in processes such as supply chain management (SCM). Systems automation holds the promise to augment the ability of supply chain operations or supply networks to rapidly adapt to changes, with minimal human intervention, under ideal conditions. Business communities are emerging as loose federations or organization of networks that may evolve to act as infomediaries in global SCM. These changes, although sluggish, are likely to impact process knowledge and in turn may be stimulated or inhibited by the availability or lack of process interoperability, respectively. The latter will determine operational efficiencies of supply chains. Currently “community of systems” or organization of networks (aligned by industry or business focus) contribute minimally in SCM decisions because true collaboration remains elusive. Convergence and maturity of multiple advances offers the potential for a paradigm shift in interoperability. It may evolve hand-in-hand with [a] the gradual adoption of the semantic web [2] with concomitant development of ontological frameworks, [b] increase in use of multi-agent systems and [c] advent of ubiquitous computing enabling near real-time access to identification of objects and analytics [4]. This paper examines some of these complex trends and related technologies. Irrespective of the characteristics of information systems, the development of various industry-contributed ontologies for knowledge and decision layers, may spur self-organizing networks of business communities and systems to increase their ability to sense and respond, more profitably, through better enterprise and extraprise exchange. In order to transform this vision into reality, systems automation must be weaned from the syntactic web and integrated with the organic growth of the semantic web. Understanding of process semantics and incorporation of intelligent agents with access to ubiquitous near real-time data “bus” are pillars for “intelligent” evolution of decision support systems. Software as infrastructure may integrate plethora of agent colonies through improved architectures (such as, service oriented architecture or SOA) and business communities aligned by industry or service focus may emerge as hubs of such agent empires. However, the feasibility of the path from exciting “pilots” in specific areas toward an informed convergence of systemic real-world implementation remains unclear and fraught with hurdles related to gaps in knowledge transfer from experts in academia to real-world practitioners. The value of interoperability between systems that may catalyse real-time intelligent decision support is further compromised by the lack of clarity of approach and tools. The latter offers significant opportunities for development of tools that may segue to innovative solutions approach. A critical mass of such solutions may spawn the necessary systems architecture for intelligent interoperability, essential for sustainable profitability and productivity in an intensely competitive global economy. This paper addresses some of these issues, tools and solutions that may have broad applicability in several operations including the management of adaptive supply-demand networks [7]. Sat, 01 Jul 2006 00:00:00 GMT https://hdl.handle.net/1721.1/102798 2006-07-01T00:00:00Z https://hdl.handle.net/1721.1/102797 Screening for Real Options “In” an Engineering System: A Step Towards Flexible System Development; PART I: The Use of Design Matrices to Create an End-to-End Representation of a Complex Socio-Technical System Bartolomei, Jason E.; de Neufville, Richard; Hastings, Daniel E.; Rhodes, Donna H. The goal of this research is to develop an analytical framework for screening for real options “in” an engineering system. Real options is defined in the finance literature as the right, but not the obligation, to take an action (e.g. deferring, expanding, contracting, or abandoning) at a predetermined cost and for a predetermined time. These are called "real options" because they pertain to physical or tangible assets, such as equipment, rather than financial instruments. Real options improve a system’s capability of undergoing classes of changes with relative ease. This property is often called “flexibility.” Recently, the DoD has emphasized the need to develop flexible system in order to improve operational, technical, and programmatic effectiveness. The aim of this research is to apply real options thinking to weapon acquisitions in order to promote the ability of weapon system programs to deftly avoid downside consequences or exploit upside opportunities. The practice of real options in systems engineering is a nascent field of inquiry. One of the most significant challenges in applying real options to engineering systems is the problem of identifying the most efficacious points within the system to create options. In order to identify the points of interest, systems engineers require knowledge about the physical and non physical aspects of the system, insight into sources of change, and the ability to examine the dynamic behavior of the system. We propose a two-phase process to perform this analysis. The first phase is a system representation phase that seeks to create an end-to-end representation of engineering system that includes endogenous interactions across system views and interactions with a systems environment. The next phase is an analysis phase that models the evolution of the engineering system in order to identify the real options in the system. This paper presents the system representation phase and proposes a methodology for creating an end-to-end representation of an engineering system. The methodology for representing an engineering system extends existing systems engineering and architecting methods in two dimensions. First, the framework couples traditional architecting views to represent traceability and endogenous interactions within an engineering system. Second, the framework includes views of the system not represented in traditional engineering frameworks that includes social networks and environmental interactions. The framework uses coupled Design Structure Matrices (DSM) to represent the traditional and new architecting views. The coupled DSMs are organized into an Engineering System Matrix (ESM), which is a holistic representation of an engineering system that captures all of the critical variables and causal interactions across architectural elements. The result is an analytic framework that captures the qualitative understanding of the system into a single view that is conducive for deep quantitative inquiry. This paper presents a discussion of pertinent literature, an overview of the ESM framework and underlying theory. In addition, this paper previews ongoing research using the ESM to identify options for a mini-air vehicle (MAV) weapon development system. Mon, 01 May 2006 00:00:00 GMT https://hdl.handle.net/1721.1/102797 2006-05-01T00:00:00Z https://hdl.handle.net/1721.1/102785 Encouraging and Ensuring Successful Technology Transition in Civil Aviation Marais, Karen; Weigel, Annalisa Technology transitions are essential to transforming air traffic management to meet future capacity needs. Encouraging and obtaining equipage adoption is one crucial aspect of technology transitions. We propose an approach for developing appropriate strategies to persuade aviation stakeholders to transition to new technologies. Our approach uses cost, benefit, and value distribution across stakeholders and over time to determine which strategies are most appropriate to persuading aircraft operators to adopt new equipage. Equipage that may show an overall positive value can nevertheless fail to provide value to individual stakeholders. Such imbalances in value distribution between stakeholders or over time may lead to stakeholder intransigence and can stymie efforts to transform air traffic management systems. Leverage strategies that correct these imbalances and accelerate the realization of value for all stakeholders can enhance cooperation and increase the likelihood of a successful transition to the new technology. We demonstrate the application of the approach using the case of automatic dependent surveillance-broadcast (ADS-B). The approach is also applicable to a wide range of industries beyond aviation, such as the energy sector and telecommunications. Wed, 01 Mar 2006 00:00:00 GMT https://hdl.handle.net/1721.1/102785 2006-03-01T00:00:00Z https://hdl.handle.net/1721.1/102784 Transition challenges for alternative fuel vehicle and transportation systems Struben, Jeroen; Sterman, John Automakers are now developing alternatives to internal combustion engines (ICE), including hydrogen fuel cells and ICE-electric hybrids. Adoption dynamics for alternative vehicles are complex due to the enormous size and importance of the auto industry and vehicle fleet. Diffusion of alternative vehicles is both enabled and constrained by powerful positive feedbacks arising from scale and scope economies, R&D, learning by doing, driver experience, word of mouth, and complementary resources such as fueling infrastructure. We describe a dynamic model of the diffusion and competition among alternative fuel vehicles, including the coevolution of the fleet, technology, driver behavior, and complementary resources. Here we focus on the generation of consumer awareness of alternatives through feedback from driving experience, word of mouth and marketing, with a reduced form treatment of network effects and other positive feedbacks (which we treat in other papers). We demonstrate the existence of a critical threshold for sustained adoption of alternative technologies, and show how the threshold depends on economic and behavioral parameters. We show that word of mouth from those not driving an alternative vehicle is important in stimulating diffusion. Nevertheless, marketing and subsidies for alternatives to ICE must remain in place for long periods for diffusion to become self-sustaining. Expanding the model boundary to include endogenous learning, technological spillovers and spatial coevolution of fueling infrastructure adds additional feedbacks that further suppress the diffusion of alternative vehicles. Mon, 01 Feb 2016 00:00:00 GMT https://hdl.handle.net/1721.1/102784 2016-02-01T00:00:00Z https://hdl.handle.net/1721.1/102783 Context Mediation Demonstration of Counter-Terrorism Intelligence (CTI) Integration Madnick, Stuart E.; Moulton, Allen; Siegel, Michael D. Examination of intelligence failures prior to the 9/11/01 attacks made clear it that lack of effective information exchange among government agencies hindered the capability of identifying potential threats and preventing terrorist actions. A 2002 National Research Council study noted that “Although there are many private and public databases that contain information potentially relevant to counterterrorism programs, they lack the necessary context definitions (i.e., metadata) and access tools to enable interoperation with other databases and the extraction of meaningful and timely information.”[14] This report clearly recognized the importance of problems that the semantic data integration research community has been studying. Wed, 01 Feb 2006 00:00:00 GMT https://hdl.handle.net/1721.1/102783 2006-02-01T00:00:00Z https://hdl.handle.net/1721.1/102781 Understanding & Modeling State Stability: Exploiting System Dynamics Choucri, Nazli; Electris, Christi; Goldsmith, Daniel K.; Mistree, Dinsha; Madnick, Stuart E.; Morrison, J. Bradley; Siegel, Michael D.; Sweitzer-Hamilton, Margaret The potential loss of state stability in various parts of the world is a source of threat to U.S. national security. Every case is unique, but there are common processes. Accordingly, we develop a system dynamics model of state stability by representing the nature and dynamics of ‘loads’ generated by insurgency activities, on the one hand, and by articulating the core features of state resilience and its ‘capacity’ to withstand these ‘loads’, on the other. The problem is to determine and ‘predict’ when threats to stability override the resilience of the state and, more important, to anticipate propensities for ‘tipping points’, namely conditions under which small changes in anti-regime activity can generate major disruptions. On this basis, we then identify appropriate actionable mitigation factors to decrease the likelihood of ‘tipping’ and enhance prospects for stability. Wed, 01 Feb 2006 00:00:00 GMT https://hdl.handle.net/1721.1/102781 2006-02-01T00:00:00Z https://hdl.handle.net/1721.1/102780 Policy for the Protection and Reuse of Non-Copyrightable Database Contents Zhu, Hongwei With the increasing use of the Internet, many of us feel strongly about the free and unfettered exchange and use of information. But the actual situation is not that simple. After the European Union adopted the Database Directive to provide legal protection for non-copyrightable database contents, the U.S. has introduced six legislative proposals, all of which failed to become a law. One of the major difficulties of formulating a socially beneficial database law is in finding the right balance between protecting the incentives of creating publicly accessible databases (including semi-structured web sites) and preserving adequate access to factual data for value creating activities. We address the problem by developing an extended spatial competition model that explicitly considers the inefficiencies in policy administration. With the model, we can determine various conditions and the corresponding socially beneficial policy choices. The results show that, depending on the cost level of database creation, the degree of differentiation of the reuser database, and the efficiency of policy administration, the socially beneficial policy choice can be protecting a legal monopoly, encouraging competition via compulsory licensing, discouraging voluntary licensing, or even allowing free riding. The results provide useful insights to the formulation of a socially beneficial database protection policy. Wed, 01 Feb 2006 00:00:00 GMT https://hdl.handle.net/1721.1/102780 2006-02-01T00:00:00Z https://hdl.handle.net/1721.1/102779 Measuring Broadband’s Economic Impact Lehr, William Herndon; Osorio, Carlos; Gillett, Sharon E.; Sirbu, Marvin A. Does broadband matter to the economy? Numerous studies have focused on whether there is a digital divide, on regulatory impacts and investment incentives, and on the factors influencing where broadband is available. However, given how recently broadband has been adopted, little empirical research has investigated its economic impact. This paper presents estimates of the effect of broadband on a number of indicators of economic activity, including employment, wages, and industry mix, using a cross-sectional panel data set of communities (by zip code) across the United States. We match data from the FCC (Form 477) on broadband availability with demographic and other economic data from the US Population Censuses and Establishment Surveys. We find support for the conclusion that broadband positively affects economic activity in ways that are consistent with the qualitative stories told by broadband advocates. Even after controlling for community-level factors known to influence broadband availability and economic activity, we find that between 1998 and 2002, communities in which mass-market broadband was available by December 1999 experienced more rapid growth in (1) employment, (2) the number of businesses overall, and (3) businesses in IT-intensive sectors. In addition, the effect of broadband availability by 1999 can be observed in higher market rates for rental housing in 2000. We compare state-level with zip-code level analyses to highlight data aggregation problems, and discuss a number of analytic and data issues that bear on further measurements of broadband’s economic impact. This analysis is perforce preliminary because additional data and experience are needed to more accurately address this important question; however, the early results presented here suggest that the assumed (and oft-touted) economic impacts of broadband are both real and measurable. Wed, 01 Feb 2006 00:00:00 GMT https://hdl.handle.net/1721.1/102779 2006-02-01T00:00:00Z https://hdl.handle.net/1721.1/102778 Managing Shared Access to a Spectrum Commons Lehr, William Herndon; Crowcroft, Jon The open access, unlicensed or spectrum commons approach to managing shared access to RF spectrum offers many attractive benefits, especially when implemented in conjunction with and as a complement to a regime of marketbased, flexible use, tradable licensed spectrum ([Benkler02], [Lehr04], [Werbach03]). However, as a number of critics have pointed out, implementing the unlicensed model poses difficult challenges that have not been well-addressed yet by commons advocates ([Benjam03], [Faulhab05], [Goodman04], [Hazlett01]). A successful spectrum commons will not be unregulated, but it also need not be command & control by another name. This paper seeks to address some of the implementation challenges associated with managing a spectrum commons. We focus on the minimal set of features that we believe a suitable management protocol, etiquette, or framework for a spectrum commons will need to incorporate. This includes: (1) No transmit only devices; (2) Power restrictions; (3) Common channel signaling; (4) Mechanism for handling congestion and allocating resources among users/uses in times of congestion; (5) Mechanism to support enforcement (e.g., established procedures to verify protocol is in conformance); (6) Mechanism to support reversibility of policy; and (7) Protection for privacy and security. We explain why each is necessary, examine their implications for current policy, and suggest ways in which they might be implemented. We present a framework that suggests a set of design principles for the protocols that will govern a successful commons management regime. Our design rules lead us to conclude that the appropriate Protocols for a Commons will need to be more liquid ([Reed05]) than in the past: (1) Marketbased instead of C&C; (2) Decentralized/distributed; and, (3) Adaptive and flexible (Anonymous, distributed, decentralized, and locally responsive). Wed, 01 Feb 2006 00:00:00 GMT https://hdl.handle.net/1721.1/102778 2006-02-01T00:00:00Z https://hdl.handle.net/1721.1/102777 Degree Correlations and Motifs in Technological Networks Whitney, Daniel E. Recent network research has sought to characterize complex systems with a number of statistical metrics, such as power law exponent (if any), clustering coefficient, community behavior, and degree correlation. A larger goal of such research is to obtain insight into the systems’ functions by means of these and similar analyses. In this paper we examine network models of mechanical assemblies. Such systems are well understood functionally. We show that they have both rich and varied community structure as well as negative degree correlations (disassortative mixing), and show that this can be explained by additional powerful constraints that arise from identifiable first principles. In addition, we note that their main “motif” is closed loops (as it is for electric and electronic circuits), a pattern that conventional network analysis does not detect but which is used by software designed to aid in the design of such systems. The implication is that functional understanding of complex systems requires considerable domain knowledge beyond what typical network analysis tools employ. Mon, 01 Aug 2005 00:00:00 GMT https://hdl.handle.net/1721.1/102777 2005-08-01T00:00:00Z https://hdl.handle.net/1721.1/102776 Analysis of the Malaysian Toll Road Public-Private Partnership Program and Recommendations for Policy Improvements Ward, John L.; Sussman, Joseph M. Malaysia has relied on toll road public-private partnerships (PPPs) for over twenty years to provide important highway infrastructure. The program has been active with nearly 1800 kilometers either constructed or concessions agreed to. The public has been less supportive of the program due to low transparency and little public involvement. Public protests are common, which may lead to long-term program instability. The CLIOS Process, developed at MIT, is applied to Malaysia’s toll road PPP program to develop new policies that can better meet these public concerns while maintaining the financial viability of the sector. With increases in transparency and public involvement, the political risks of the program should be reduced and long-term stability for the government and concessionaires improved. We argue that the focus should be at the regional transportation planning level where toll road PPPs can be compared with alternatives for meeting transportation needs rather than at the national level where Malaysian toll road PPPs are currently handled. Mon, 01 Aug 2005 00:00:00 GMT https://hdl.handle.net/1721.1/102776 2005-08-01T00:00:00Z https://hdl.handle.net/1721.1/102775 Using Design Structure Matrices to Improve Decentralized Urban Transportation Systems Dunn, Travis P.; Sussman, Joseph M. Management of large, complex, urban transportation systems involves numerous stakeholders due to the decentralized ownership and operation of distinct pieces of the physical network and services. In order to deliver better service to users, many urban regions are adopting technological and operational solutions, both of which necessitate interaction among the decentralized organizations. This research applies systems engineering analysis techniques—the design structure matrix (DSM) and clustering—in order to improve the efficiency and effectiveness of organizational interactions between agencies as they deploy Intelligent Transportation Systems (ITS) and attempt to integrate their operations. Specifically, we examine the application of clustering to the institutional structure set forth by the Regional ITS Architecture for metropolitan Seattle. Mon, 01 Aug 2005 00:00:00 GMT https://hdl.handle.net/1721.1/102775 2005-08-01T00:00:00Z https://hdl.handle.net/1721.1/102774 Characterizing Three Engineering Systems Methods for Supporting Regional Strategic Transportation Planning Applied to Freight Systems Sgouridis, Sgouris P.; Sussman, Joseph M.; Glazner, Christopher A systems perspective for regional strategic transportation planning (RSTP) for freight movements involves an understanding of Supply Chain Management (SCM). This paper starts from the premise that the public sector needs to enhance economic development in the form of providing and ensuring the operation of sufficient network capacity for freight needs but at the same time secure the region’s long term environmental and societal well being. The need for long-term integrated transportation planning that is sensitive to supply chain needs and environmental nuances can be supported by the use of engineering systems methodologies. Here we demonstrate the use and potential of three such methods: Design Structure Matrix (DSM), System Architecture (SA) and System Dynamics in support of a transportation planning process that integrates SCM considerations into RSTP. Mon, 01 Aug 2005 00:00:00 GMT https://hdl.handle.net/1721.1/102774 2005-08-01T00:00:00Z https://hdl.handle.net/1721.1/102773 Multi-Airport Systems in the Era of No-Frills Airlines de Neufville, Richard The development of no-frills airlines is promoting a remarkable expansion in the number of secondary airports in major metropolitan areas. These new carriers are creating a significant alternative to the traditional full-service carriers. In effect, they are establishing a parallel market and corresponding network of airports. This conclusion results from the analysis of a worldwide database on major metropolitan airports. This effect supplements the "number of originating passengers", that has been the traditional significant factor that promotes the establishment of viable multi-airport systems. This factor maintains its importance, but no longer is as decisive as it has been. Airlines and airport policies further reinforce the independent network of secondary airports. Nofrills airlines that sell only through the web to customers effectively cause their services at secondary airports to disappear from the airline reservation systems. Airports that choose not to provide low-cost service to no-frills airlines likewise strengthen the role of the secondary airports. Such strategies, most visible in Europe, have led to a remarkable proliferation of secondary airports in unexpected areas. This trend implies a traffic shift away from the expensive, congested airports toward the no-frills, inexpensive and uncongested airports in major metropolitan areas. If the current major airlines do shrink substantially, as could happen, this would greatly change the pattern of airport traffic in major metropolitan areas. Wed, 01 Jun 2005 00:00:00 GMT https://hdl.handle.net/1721.1/102773 2005-06-01T00:00:00Z https://hdl.handle.net/1721.1/102772 Building Real Options into Physical Systems with Stochastic Mixed-Integer Programming Wang, Tao; de Neufville, Richard The problem of building real options into physical systems has three features: real options are not as easily defined as financial options; path-dependency and interdependencies among projects mean that the standard tools of options analysis tools are insufficient; and the focus is on identifying the best way to build flexibility into the design – not to value individual options. This paper suggests a framework for exploring real options in physical systems that especially addresses these two difficulties. This framework has two stages: options identification and options analysis. The options identification stage consists of screening and simulation models that focus attention on a small subset of the possible combination of projects. The options analysis stage uses stochastic mixed-integer programming to manage the path-dependency and interdependency features. This stochastic formulation enables the analyst to include more technical details and develop explicit plans for the execution of projects according to the contingencies that arise. The paper illustrates the approach with a case study of a water resources planning problem, but the framework is generally applicable to a variety of large-scale physical systems. Wed, 01 Jun 2005 00:00:00 GMT https://hdl.handle.net/1721.1/102772 2005-06-01T00:00:00Z https://hdl.handle.net/1721.1/102771 Management of Technology Investment Risk with Real Options-Based Design: A case study of an innovative building technology Greden, Lara; de Neufville, Richard; Glicksman, Leon R. Implementation of innovative technologies is hindered by the perceived risks of technical failure or increased first cost. However, by designing a system to include real options within its architecture and by recognizing the value in operational flexibility, the project’s value is structured to avoid downside risks yet benefit from upside opportunities. A real options based methodology for innovative engineering system design consists of identifying relevant uncertainties, designing options “in” the system, and modeling the performance of the options-based design subject to the uncertainties. The results guide decision makers on how much to spend on the design and construction of a flexible system. A case study of the market value of an innovative naturally ventilated building with embedded option to install mechanical cooling in the future demonstrates how the option “in” the system protects the asset from downside outcomes in market value yet allows it to benefit from upside opportunities. Wed, 01 Jun 2005 00:00:00 GMT https://hdl.handle.net/1721.1/102771 2005-06-01T00:00:00Z https://hdl.handle.net/1721.1/102770 Value-at-Risk Analysis for Real Options in Complex Engineered Systems Hassan, Rania; de Neufville, Richard; de Weck, Olivier L.; Hastings, Daniel E.; McKinnon, Douglas This paper presents a simple but powerful Real Options Valuation methodology suitable for valuing flexibility in complex engineered systems. It is based on value-at-risk analysis and relies on a standard discounted cash flow approach. A case study on the architecting of flexible satellite fleets is presented. The architecting framework integrates spacecraft engineering design with economic analysis for the purpose of maximizing the financial value of a fleet to the operator under uncertain, evolving market conditions. The investigation considers the forecasted demand evolution for a satellite service in two distant geographical markets simultaneously and provides flexible fleet architectures that significantly improve various aspects of the value-at-risk distributions compared to those of a traditional, rigid fleet architecture. It is shown that the flexible architectures are able to capture more revenue, mitigate more risk and/or reduce overall required investment. The suggested Real Options “in” the system, rather than “on” the system, approach allows engineers, strategists, or decision makers in engineering establishments to embed flexibility in the design of complex systems for the purpose of maximizing their total lifetime value. Wed, 01 Jun 2005 00:00:00 GMT https://hdl.handle.net/1721.1/102770 2005-06-01T00:00:00Z https://hdl.handle.net/1721.1/102769 Semantic Information Integration in the Large: Adaptability, Extensibility, and Scalability of the Context Mediation Approach Gannon, Thomas; Madnick, Stuart E.; Moulton, Allen; Siegel, Michael D.; Sabbouh, Marwan; Zhu, Hongwei There is pressing need for effectively integrating information from an ever increasing number of available sources both on the web and in other existing systems. A key difficulty of achieving this goal comes from the pervasive heterogeneities in all levels of information systems. Existing and emerging technologies, such as the Web, ODBC, XML, and Web Services, provide essential capabilities in resolving heterogeneities in the hardware and software platforms, but they do not address the semantic heterogeneity of the data itself. A robust solution to this problem needs to be adaptable, extensible, and scalable. In this paper, we identify the deficiencies of traditional approaches that address this problem using hand-coded programs or require complete data standardization. The COntext INterchange (COIN) approach overcomes these deficiencies by declaratively representing data semantics and using a mediator to create the necessary conversion programs using a small number of conversion rules. The capabilities of COIN is demonstrated using an intelligence information integration example consisting of 150 data sources, where COIN can automatically generate the over 22,000 conversion programs needed to enable semantic integration using only six parametizable conversion rules. This paper makes a unique contribution by providing a systematic evaluation of COIN and other commonly practiced approaches. Sun, 01 May 2005 00:00:00 GMT https://hdl.handle.net/1721.1/102769 2005-05-01T00:00:00Z https://hdl.handle.net/1721.1/102768 Research Initiative to Understand & Model State Stability: Exploiting System Dynamics Choucri, Nazli In its Preface, The 9/11 Commission Report states: “We learned that the institutions charted with protecting …national security did not understand how grave this threat can be, and did not adjust their policies, plans, and practices to deter or defeat it” (2004: xvi). Given current realities and uncertainties “better preparedness” can be achieved by identifying, controlling and managing the elusive linkages and situational factors that impact state stability and fuel state decay and destruction – and hence create new threats to the nation’s security. We propose to focus on the use of system dynamics modeling techniques to help understand, measure and model the complex dynamics shaping state stability, initially for two regions. We will specifically consider the impacts of unanticipated disruptions, such as a tsunami and its aftermath, on the dynamics of the two regions. For each region, we will deliver a detailed country model, including 3-5 futures predictions in the 6-12 month range along with an analysis of conditions and casual links between predicted futures plus corresponding mitigated options. Tue, 01 Feb 2005 00:00:00 GMT https://hdl.handle.net/1721.1/102768 2005-02-01T00:00:00Z https://hdl.handle.net/1721.1/102767 Model-Based Analysis of Socio-Technical Risk Leveson, Nancy G. Traditional approaches to hazard analysis and safety-related risk management are based on an accident model that focuses on failure events in static engineering designs and linear notions of causality. They are therefore limited in their ability to include complex human decision-making, software errors, system accidents (versus component failure accidents), and organizational risk factors in the analysis. These traditional accident models do not adequately capture the dynamic complexity and non-linear interactions that characterize accidents in complex systems, i.e., what Perrow called system accidents. System accidents often result from adaptation and degradation of safety over time: The move to a high-risk state occurs without any particular decision to do so but simply as a series of decisions or adaptations (asynchronous evolution) that move the system into a high-risk state where almost any slight error or deviation can lead to a major loss. To handle this more comprehensive view of accidents, risk management tools and models need to treat systems as dynamic processes that are continually adapting to achieve their ends and to react to changes in themselves and their environment. Leveson’s new accident model, STAMP (Systems-Theoretic Accident Modeling and Processes), provides the foundation for such a risk management approach by describing the process leading up to an accident as an adaptive feedback function that fails to maintain safety constraints as performance changes over time to meet a complex set of goals and values. In this report, a new type of hazard analysis based on this new model of accident causation is described called STPA (STAMP-based Analysis). STPA is illustrated by applying it to TCAS II, a complex aircraft collision avoidance system, and to a public water safety system in Canada. In the first example (TCAS II), STPA is used to analyze an existing system design. A formal and executable modeling/specification language called SpecTRM-RL is used to model and simulate the technical and human components in the system and to provide the support required for the STPA analysis. The results are compared with traditional hazard analysis techniques, including a high-quality TCAS II fault tree analysis created by MITRE for the FAA. The STPA analysis was found to be more comprehensive and complete than the fault tree analysis. The second example of STPA (the public water system) illustrates its application to the organizational and social components of open systems as well as the technical. In this example, STPA is used to drive the design process rather than to evaluate an existing design. Again, SpecTRM-RL models are used to support the analysis, but this time we added system dynamics models. SpecTRM-RL allows us to capture the system’s static structure (hardware, software, operational procedures, and management controls) and is useful in performing hazard analyses that examine complex socio-technical safety control structures. The addition of system dynamics models allows simulation and modeling of the system’s behavioral dynamics and the effects of changes over time. STPA allowed us to examine the impact of organizational decision-making and technical design decisions on system risk and resiliency. The integration of STPA, SpecTRM-RL, and system dynamics creates the potential for a simulation and analysis environment to support and guide the initial technical and operational system design as well as organizational and management policy design. The results of STPA analysis can also be used to support organizational learning and performance monitoring throughout the system’s life cycle so that degradation of safety and increases in risk can be detected before a catastrophe results. Wed, 01 Dec 2004 00:00:00 GMT https://hdl.handle.net/1721.1/102767 2004-12-01T00:00:00Z https://hdl.handle.net/1721.1/102766 Connectivity Limits of Mechanical Assemblies Modeled as Networks Whitney, Daniel E. This paper applies network connectivity analysis to mechanical assemblies. Assemblies have extensive intentional structure while simultaneously displaying some of the properties of previously analyzed networks. Fundamental principles impose restrictions on the structure of assemblies, as do some practical principles. Fundamental restrictions stem from the desire to avoid over-constraining the assembly. Practical restrictions stem from the desire to limit the complexity of the assembly or any significant subassembly. These restrictions play a role analogous to the cost of connection. For these reasons, mechanical assemblies are unlikely to exhibit scale-free properties common in many natural systems and some man-made ones. Mon, 01 Nov 2004 00:00:00 GMT https://hdl.handle.net/1721.1/102766 2004-11-01T00:00:00Z https://hdl.handle.net/1721.1/102765 Improving UccNet-Compliant B2B Supply-Chain Applications Using a Context Interchange Framework Tu, Steven Yi-Cheng; Madnick, Stuart E.; Wu, Luis Chin-Jung UccNet (http://knowledgebase.uccnet.org) is a globally centralized B2B electronic data platform for storing trading product item information and hosted by the non-profit international standardization institute EAN-UCC. It is an emerging B2B data communication standard for the retail industry with significant potential impact. Many US retailers are requesting their international suppliers for compulsory subscription by the year-end of either 2004 or 2005 and many major IT software providers and consulting firms specialized in supply chain management are preparing packaged services/solutions for this imminent demand. In light of the increasing importance of UccNet on both the technology and application sides, this paper attempts to advance the following argument: Though UccNet establishes an architectural framework to resolve the many-to-many connectivity issue and data synchronization issue through a centralized product database and a uniform numbering system (i.e., Global Trade Item Numbering), there are context discrepancy issues remaining to be addressed. We show with a real case study that context discrepancy is inherent in the international trading applications where UccNet is intended to be used. Naturally, international trading partners tend to define and describe product item information differently. That difference, either due to the culture or the geographical location, is not considered in the original design of UccNet. As an example, the attribute "width" contained in the database schema of UccNet would be filled by a China-based supplier in 'meter' and yet be interpreted as 'feet' by the US retail buyer. We show how the Context Interchange Framework, operating under the rationale of local autonomy and speaking to the resolution of context mediation issue, can be nicely incorporated into the existing UccNet framework to constitute theoretically a more complete technical solution and practically a more useful B2B supply chain business solution. Mon, 01 Nov 2004 00:00:00 GMT https://hdl.handle.net/1721.1/102765 2004-11-01T00:00:00Z https://hdl.handle.net/1721.1/102764 Heterogeneity and Network Structure in the Dynamics of Diffusion: Comparing Agent-Based and Differential Equation Models Rahmandad, Hazhir When is it better to use agent based (AB) models, and when should differential equation (DE) models be used? Where DE models assume homogeneity and perfect mixing within compartments, AB models can capture heterogeneity in agent attributes and in the network of interactions among them. Using contagious disease as an example, we contrast the dynamics of AB models with those of the corresponding mean-field DE model, specifically, comparing the standard SEIR model-a nonlinear DE-to an explicit AB model of the same system. We examine both agent heterogeneity and the impact of different network structures, including fully connected, random, Watts-Strogatz small world, scale-free, and lattice networks. Surprisingly, in many conditions the AB and DE dynamics are quite similar. Differences between the DE and AB models are not statistically significant on key metrics relevant to public health, including diffusion speed, peak load on health services infrastructure and total disease burden. We explore the conditions under which the AB and DE dynamics differ, and consider implications for managing infectious disease. The results extend beyond epidemiology: from innovation adoption to the spread of rumor and riot to financial panics, many important social phenomena involve analogous processes of diffusion and social contagion. Mon, 01 Nov 2004 00:00:00 GMT https://hdl.handle.net/1721.1/102764 2004-11-01T00:00:00Z https://hdl.handle.net/1721.1/102763 Order Stability in Supply Chains: Coordination Risk and the Role of Coordination Stock Croson, Rachel; Donohue, Karen; Katok, Elena; Sterman, John The bullwhip effect describes the tendency for the variance of orders in supply chains to increase as one moves upstream from consumer demand. Previous research attributes this phenomenon to both operational and behavioral causes. Operational causes are features of the institutional setting that lead rational agents to amplify changes in demand, while behavioral causes arise from suboptimal decisionmaking. This paper examines causes of the bullwhip through experiments with a serial supply chain, using the Beer Distribution Game. Unlike prior studies, we control all four commonly cited operational causes of the bullwhip, including uncertainty about customer demand. We eliminate demand uncertainty completely by making customer demand constant and known to all participants. Despite these controls, order amplification, instability, and supply line underweighting remain pervasive. We propose a new behavioral cause of the bullwhip, coordination risk, that arises when players place excessive orders to address the perceived risk that others will not behave optimally. We test two strategies to mitigate coordination risk: (1) holding additional on-hand inventory, and (2) creating common knowledge by informing participants of the optimal policy. Both strategies reduce, but not eliminate, the bullwhip effect. Holding excess inventory reduces order amplification by providing a buffer against the endogenous risk of coordination failure. Such coordination stock differs from traditional safety stock, which buffers against exogenous demand uncertainty. Surprisingly, neither strategy reduces supply-line underweighting. We conclude that the bullwhip can be mitigated but its behavioral causes appear robust. Mon, 01 Nov 2004 00:00:00 GMT https://hdl.handle.net/1721.1/102763 2004-11-01T00:00:00Z https://hdl.handle.net/1721.1/102758 A Systems Framework for Assessing Air Quality Impacts of ITS: Application to Mexico City Dodder, Rebecca S. Intelligent Transportation Systems (ITS)—the application of communications and information technology to surface transportation systems—has the potential to improve transportation along several dimensions, from safety to emissions reductions to travel time and reliability. ITS has become a worldwide technology, and many cities in Latin America are currently deploying ITS, from individual technologies to entire ITS Architectures. While improving mobility is at the core of any ITS deployment, in metropolitan areas from Mexico City to Sao Paulo, air quality concerns are such that ignoring possible air quality impacts of ITS technologies represents either a failure to leverage ITS for air quality improvements, or even a risk of running counter to air quality management efforts. While there is a growing number of studies evaluating the air quality benefits of ITS, there are important limitations on the extent to which the results of these studies can be used to support planning of ITS in cities in Latin America. First, the challenges involved in modeling ITS air quality benefits mean that they typically focus on only one or two ITS technologies at a time. Second, air quality and mobility conditions vary greatly across cities, meaning that air quality outcomes will also vary widely. Finally, from a planning standpoint, a more system-wide and qualitative framework is needed to generate the kind of dialogue needed between a diverse number of groups—environmental, transportation, public works, public security, and transport operators—to decide how ITS can meet a metropolitan area needs. In order to address these issues, I develop a systems framework that can encompass a number of ITS technologies and performance measures. Within this systems framework, I look specifically at air quality. Rather than focusing on particular modeling tools, I break down air quality impacts into eight mechanisms that can lead to decreases or increases in mobile source emissions. I will also return briefly to the literature on ITS environmental benefits, to review which mechanisms are included as variables. Finally, I will consider the case of Mexico City, and the interactions between current ITS deployments and air quality. Fri, 01 Oct 2004 00:00:00 GMT https://hdl.handle.net/1721.1/102758 2004-10-01T00:00:00Z https://hdl.handle.net/1721.1/102756 A Methodology for the Identification of Critical Locations in Infrastructures Lemon, Douglas M. The extreme importance of critical infrastructures to modern society is widely recognized. These infrastructures are complex, interdependent, and ubiquitous; they are sensitive to disruptions that can lead to cascading failures with serious consequences. Protecting the critical infrastructures from terrorism, human generated malevolent attack directed toward maximum social disruption, presents an enormous challenge. Recognizing that society cannot afford the costs associated with absolute protection, it is necessary to identify the critical locations in these infrastructures. By protecting the critical locations society achieves the greatest benefit for the protection investment. This paper presents a methodology for the identification of critical locations in infrastructures. The framework models the infrastructures as interconnected digraphs and employs graph theory and reliability theory to identify the vulnerable points. The vulnerable points are screened for their susceptibility to a terrorist attack, and a prioritized list of critical locations is produced. The prioritization methodology is based on multi-attribute utility theory. The methodology is illustrated through the presentation of a portion on the analysis conducted on the campus of the Massachusetts Institute of Technology. Tue, 01 Jun 2004 00:00:00 GMT https://hdl.handle.net/1721.1/102756 2004-06-01T00:00:00Z https://hdl.handle.net/1721.1/102755 Supply Chain Management Under The Threat Of International Terrorism Sheffi, Yossi On the morning of September 11th, 2001, the United States and the Western world entered into a new era – one in which large scale terrorist acts are to be expected. The impacts of the new era will challenge supply chain managers to adjust relations with suppliers and customers, contend with transportation difficulties and amend inventory management strategies. This paper looks at the twin corporate challenges of (i) preparing to deal with the aftermath of terrorist attacks and (ii) operating under heightened security. The first challenge involves setting certain operational redundancies. The second means less reliable lead times and less certain demand scenarios. In addition, the paper looks at how companies should organize to meet those challenges efficiently and suggests a new public-private partnership. While the paper is focused on the US, it has worldwide implications. Wed, 01 May 2002 00:00:00 GMT https://hdl.handle.net/1721.1/102755 2002-05-01T00:00:00Z https://hdl.handle.net/1721.1/102754 Corporate-University Alliances and Engineering Systems Research Roth, George L.; Magee, Christopher L. This symposium is focused on the possibilities for deeper, more fundamental understanding of engineering systems. Many of the papers address characteristics of engineering systems. As noted by others, engineering systems can not be studied in the laboratory. Researchers must venture into these systems for extended periods of time and develop the academic field of study. It is essential for the MIT Engineering Systems Division to find ways for active observational and experimental work to take place in these systems. To sustain their engagement in those systems, and gain validity for their claims, researchers will need to go beyond study to affect practice. Wed, 01 May 2002 00:00:00 GMT https://hdl.handle.net/1721.1/102754 2002-05-01T00:00:00Z https://hdl.handle.net/1721.1/102753 The Anatomy of Large Scale Systems Moses, Joel Many theoretical analyses of systems emphasize their behavior. In this paper we shall emphasize the role of organizational structure in influencing certain aspects of the behavior of systems, rather than the full behavior of the systems. There are several historical examples where structure was analyzed early on in order to gain a better understanding of systems. In medicine, for example, anatomy was studied well before we had a deep understanding of the role and behavior of subsystems or infrastructures of the body, such as the liver and blood flow. Different generic structures or architectures provide different advantages and disadvantages in coping with changes in the overall environment in which an evolving system is expected to operate during its lifetime. We shall discuss some of these advantages and disadvantages for various generic structures or architectures. One difficulty in discussing systems issues is the lack of a relatively precise language and concepts for dealing with such issues. We propose that abstract algebra has at least some of the needed concepts. Tue, 01 May 2012 00:00:00 GMT https://hdl.handle.net/1721.1/102753 2012-05-01T00:00:00Z https://hdl.handle.net/1721.1/102752 Large Scale Infrastructure Systems Moavenzadeh, Fred Highways, bridges, office buildings, houses, etc. are typical large-scale infrastructure systems of physical facilities that must be planned, designed, built, operated, and maintained. In addition to physical requirements, they have complex and often farreaching interactions with the social, political, and economic systems they serve. Built facilities that have long service life times and large size represent a major commitment in terms of both capital expenditure and, equally importantly, social and political structures. Wed, 01 May 2002 00:00:00 GMT https://hdl.handle.net/1721.1/102752 2002-05-01T00:00:00Z https://hdl.handle.net/1721.1/102751 Bodies, Ideas, and Dynamics: Historical Perspectives on Systems Thinking in Engineering Mindell, David A. Today, the idea that technology consists not simply of individual machines but of systems of components and interconnections underlies much of engineering theory and practice. Yet this idea is relatively new in the history of technology; it evolved over a long period, spanning more than a century, as engineers grappled with the implications of machinery and collections of apparatus that spread over broad geographical areas. A historical perspective on systems thinking provides a critical background for contemplating new directions in “engineering systems,” by highlighting the problems that have constantly challenged engineers, as well as the new puzzles posed by today’s world. Wed, 01 May 2002 00:00:00 GMT https://hdl.handle.net/1721.1/102751 2002-05-01T00:00:00Z https://hdl.handle.net/1721.1/102750 Isoperformance An Alternative Design Methodology for Engineering Systems de Weck, Olivier L. Tradeoffs between performance, cost and risk frequently arise during architecting and design of complex Engineering Systems such as aerospace vehicles. A paradigm shift is occurring from the pure performance optimization approach of the past towards satisfying of performance targets under concurrent risk and cost minimization. This paper proposes “isoperformance” as a set based approach to designing engineering systems by first identifying the acceptable performance invariant set of designs from which a final design is chosen. This is in contrast to a multiobjective cost-risk minimization under performance equality constraints. This paper identifies a number of issues associated with finding the desired performance invariant set, I, given a deterministic or empirical system model that maps design variables x to objective variables J. Isoperformance is presented as a methodology that can quantify and visualize the tradeoffs between determinants (independent design variables) of a known or desired outcome. For deterministic systems the multivariable performance invariant contours can be computed using sensitivity analysis and a contour following algorithm, provided that a mathematical system model of appropriate fidelity exists. In the case of stochastic systems the isoperformance curves can be obtained via a regression analysis, given a statistically representative data set. Once isoperformance curves have been obtained, they are useful in extracting a set of performance invariant solutions. Applying additional objectives, other than performance, can then lead to a set of pareto-optimal designs. Specific examples from opto-mechanical space systems design and human factors are presented. Wed, 01 May 2002 00:00:00 GMT https://hdl.handle.net/1721.1/102750 2002-05-01T00:00:00Z https://hdl.handle.net/1721.1/102749 The Impact of Instability on Complex Social and Technical Systems Cutcher-Gershenfeld, Joel; Rebentisch, Eric Instability is a pervasive phenomenon that has deep implications for virtually all complex social and technical systems. In engineering, the identification and mitigation of various types of technical instabilities is a well developed practice. This is a key focus, for example, of engineers concerned about the prevention of potentially destabilizing vibration in the frame of an aircraft or the mitigation of sources of technical instability in the operation of a nuclear reactor. However, the nature of instability in complex social and technical systems is relatively unstudied and not well understood. This is unfortunate because instability can have profound effects on the performance of those systems as well as their ability to improve their performance over time. In this paper, we present a conceptual framework for understanding instability in sociotechnical systems. To illustrate what we mean by instability in the context of complex engineering systems, we will draw on data from the aerospace industry. In particular, we use two data sets, to trace the impacts of various sources of instability. One data set centers on instability and its impact on aerospace programs, while the other centers on instability and its impact on aerospace production and design facilities. Wed, 01 May 2002 00:00:00 GMT https://hdl.handle.net/1721.1/102749 2002-05-01T00:00:00Z https://hdl.handle.net/1721.1/102748 ESD Symposium Comittee Overview: Engineering Systems Research and Practice ESD Symposium Committee This paper briefly introduces the field of Engineering Systems, and highlights its emergence from engineering practice and academic engineering. This paper was prepared by the ESD Symposium Committee based upon its own discussions, by an analysis of the other Internal Symposium papers, and by interactions with their authors. This paper discusses: a framework for describing the field of engineering systems, and emphasizes a three-dimensional view the challenges emerging in engineering practice that are associated with the design of complex systems the methods that address research and practice problems (most of these methods currently exist, some must be developed) principles and fundamentals of engineering systems "Engineering systems are increasing in size, scope, and complexity as a result of globalization, new technological capabilities, rising consumer expectations, and increasing social requirements. Engineering systems present difficult design problems and require different problem solving frameworks than those of the traditional engineering science paradigm: in particular, a more integrative approach in which engineering systems professionals view technological systems as part of a larger whole. Though engineering systems are very varied, they often display similar behavior. New approaches, frameworks, and theories need to be developed to understand better engineering systems behavior and design.” Wed, 01 May 2002 00:00:00 GMT https://hdl.handle.net/1721.1/102748 2002-05-01T00:00:00Z https://hdl.handle.net/1721.1/102747 A New Accident Model for Engineering Safer Systems Leveson, Nancy G. New technology is making fundamental changes in the etiology of accidents and is creating a need for changes in the explanatory mechanisms used. We need better and less subjective understanding of why accidents occur and how to prevent future ones. The most effective models will go beyond assigning blame and instead help engineers to learn as much as possible about all the factors involved, including those related to social and organizational structures. This paper presents a new accident model founded on basic systems and control theory concepts. The use of such a model provides a theoretical foundation for the introduction of unique new types of accident analysis, hazard analysis, accident prevention strategies including new approaches to designing for safety, risk assessment techniques, and approaches to designing performance monitoring and safety metrics. Wed, 01 May 2002 00:00:00 GMT https://hdl.handle.net/1721.1/102747 2002-05-01T00:00:00Z https://hdl.handle.net/1721.1/102746 The Link between Cognition and the Complexity of Engineering Systems Design Williams, John R. This paper focuses on the role of human cognition in the design of large complex systems. It contrasts the physical system that is the product of the design with the cognitive model that is used by the designer to “understand” the system. The complexity of the system relevant to the designer is a function not only of the physical system, but also of the cognitive model that the designer holds in his mind. Furthermore, the level of cognitive model available to an experienced designer depends on the state of domain knowledge. To be useful in answering the question, “How complex is this system to design?” the state of the domain knowledge available to the designer must be assessed with respect to the level at which the design problem is posed. The concept of conceptual distance is introduced that depends on the disparity between the present level of integrated knowledge and the conceptual level of the design problem. This “distance” is a measure of the complexity of the design task and is called the cognitive complexity of the design. To investigate the concept of cognitive complexity a model of human knowledge is proposed along with a set of graphical abstractions. It is concluded that the cognitive complexity of the design task is neither wholly intrinsic (a property of the system) nor wholly subjective (a property of the mind) but requires an objective evaluation of the engineering problem with respect to present knowledge. It is noted that the structure of knowledge in a specific domain can be mapped and therefore a research program can be launched to systematically determine the difficulty of various engineering endeavors. Wed, 01 May 2002 00:00:00 GMT https://hdl.handle.net/1721.1/102746 2002-05-01T00:00:00Z https://hdl.handle.net/1721.1/102745 Bits and Bucks: Modeling complex systems by information flow Lloyd, Seth This paper presents a general method for modeling and characterizing complex systems in terms of flows of information together with flows of conserved or quasi-conserved quantities such as energy or money. Using mathematical techniques borrowed from statistical mechanics and from physics of computation, a framework is constructed that allows general systems to be modeled in terms of how information, energy, money, etc. flow between subsystems. Physical, chemical, biological, engineering, and commercial systems can all be analyzed within this framework. Wed, 01 May 2002 00:00:00 GMT https://hdl.handle.net/1721.1/102745 2002-05-01T00:00:00Z https://hdl.handle.net/1721.1/102744 Complex systems: a review Lloyd, Seth Engineers have worked on complex systems ever since engineering began. But the sciences of complexity have come in to their own in the last few decades. Hoping to find common threads that weave their disciplines together, researchers from the fields of physics, biology, chemistry, math, computer science, economics, anthropology, linguistics, et al. have banded together to try to develop unifying frameworks for understanding complex systems. This paper reports on successes and failures of these efforts. Wed, 01 May 2002 00:00:00 GMT https://hdl.handle.net/1721.1/102744 2002-05-01T00:00:00Z https://hdl.handle.net/1721.1/102743 Nano-technology: a Disruptive Technology? Utterback, James M.; Acee, Happy J. The term "disruptive technology" as coined by Christensen (1997) refers to a new technology having lower cost and performance measured by traditional criteria, but having higher ancillary performance. Christensen finds that disruptive technologies may enter and expand emerging market niches, improving with time and ultimately attacking established products in their traditional markets. This conception, while useful, is also limiting in several important ways. By emphasizing only "attack from below" Christensen ignores other discontinuous patterns of change which may be of equal or greater importance (Utterback, 1994; Acee, 2001). Further, the true importance of disruptive technology, even in Christensen's conception of it is not that it may displace established products. Rather, it is a powerful means for enlarging and broadening markets and providing new functionality. In this paper nano-technologies will be considered in their roles as both disruptive and more broadly discontinuous or radical innovation. Various impacts will be assessed with emphasis on enlarged and new markets that may be created. Wed, 01 May 2002 00:00:00 GMT https://hdl.handle.net/1721.1/102743 2002-05-01T00:00:00Z https://hdl.handle.net/1721.1/102742 Lean Enterprises – A Systems Perspective Nightingale, Deborah J. Becoming a “Lean Enterprise” is increasingly being recognized as an important strategy in achieving critical strategic goals such as responsiveness, cycle time and cost across all phases of the product life cycle. The concept of a lean enterprise is not new. Many books address lean enterprise topics. For example, The Machine That Changed the World, the book that introduced lean terminology, has a chapter on “Managing Lean Enterprises”. Despite having much written on this subject, lean enterprises are only starting to emerge in practice. Why has it taken so long to transform organizations to lean enterprises? Lean enterprises are complex, highly integrated systems comprised of processes, products, organizations, and information, with multifaceted interdependencies and interrelationships across their boundaries. Understanding, engineering, and managing these complex social, technical, and infrastructure processes are critical to becoming a lean enterprise. Wed, 01 May 2002 00:00:00 GMT https://hdl.handle.net/1721.1/102742 2002-05-01T00:00:00Z https://hdl.handle.net/1721.1/102741 System Dynamics: Systems Thinking and Modeling for a Complex World Sterman, John Todays problems often arise as unintended consequences of yesterdays solutions. Social systems often suffer from policy resistance, the tendency for well-intentioned interventions to be defeated by the response of the system to the intervention itself. The field of system dynamics, created at MIT in the 1950s by Jay Forrester, is designed to help us learn about the structure and dynamics of the complex systems in which we are embedded, design high-leverage policies for sustained improvement, and catalyze successful implementation and change. Drawing on engineering control theory and the modern theory of nonlinear dynamical systems, system dynamics often involves the development of formal models and management flight simulators to capture complex dynamics, and to create an environment for learning and policy design. Unlike pure engineering problems if any exist, human systems present unique challenges, including long time horizons, issues that cross disciplinary boundaries, the need to develop reliable models of human behavior, and the great difficulty of experimental testing. Successful change in social systems also requires the active participation of a wide range of people in the modeling and policy design process, people who often lack technical training. In this paper I discuss requirements for the effective use of system dynamics and illustrate with a successful application to a difficult business issue. Wed, 01 May 2002 00:00:00 GMT https://hdl.handle.net/1721.1/102741 2002-05-01T00:00:00Z https://hdl.handle.net/1721.1/102740 Defining Engineering Systems: Investigating National Missile Defense Zuckerman, Brian The MIT Engineering Systems Division is currently building its intellectual framework. There is not yet consensus within ESD as to which tools and methods are central to the nascent engineering systems approach; which questions it should address; or the extent to which qualitative approaches should be incorporated into it. The goal of this paper is to sharpen the debate by presenting multiple analyses of a single engineering system. Presenting varying perspectives illuminates issues such as: What types of questions should engineering systems practitioners ask when analyzing problems? Which tools are fundamental, which are peripheral, and which lie outside its purview? Is there a trade-off between the analytical rigor of different tools and the degree to which they can address questions the approach considers important? Does this approach suggest generalizable principles for analyzing engineering systems? This paper uses national missile defense (NMD) as the analytical vehicle for this approach. By any definition, NMD is an engineering system. Moreover, the complexity of NMD facilitates the framing of analyses on multiple levels, and provides a mechanism for exploring the ramifications of different potential definitions of “engineering systems” as a discipline. Finally, the issue is policy-relevant. The United States is currently deciding how to build and deploy NMD; the choice of system architectures may have important cost, foreign policy, military readiness, and domestic political ramifications. While there is considerable descriptive information about system components, there is little hard data in the open literature regarding system performance and costs. This paper draws upon the available literature, while making estimates where necessary. Wed, 01 May 2002 00:00:00 GMT https://hdl.handle.net/1721.1/102740 2002-05-01T00:00:00Z https://hdl.handle.net/1721.1/102739 Learning from Organizational Experience Carroll, John Stephen; Rudolph, Jenny W.; Hatakenaka, Sachi Learning-in-action, the cyclical interplay of thinking and doing, is increasingly important for organizations as environments and required capabilities become more complex and interdependent. Organizational learning involves both a desire to learn and supportive structures and mechanisms. We draw upon three case studies from the nuclear power and chemical industries to illustrate a four-stage model of organizational learning: (1) local stage of decentralized learning by individuals and work groups, (2) control stage of fixing problems and complying with rules, (3) open stage of acknowledgement of doubt and motivation to learn, and (4) deep learning stage of skillful inquiry and systemic mental models. These four stages differ on whether learning is primarily single-loop or doubleloop, i.e., whether the organization can surface and challenge the assumptions and mental models underlying behavior, and whether learning is relatively improvised or structured. The case studies illustrate how organizations learn differently from experience, the details of learning practices, and the nature of stage transitions among learning practices. Wed, 01 May 2002 00:00:00 GMT https://hdl.handle.net/1721.1/102739 2002-05-01T00:00:00Z https://hdl.handle.net/1721.1/102738 A Control Engineering Approach to Making Complex Infrastructures More Efficient and Reliable: A Core Program for ESD Ilic, Marija Many of our national infrastructures, such as electric power, gas pipeline, transportation and information/communication systems suffer from common design, planning and operating problems. As a consequence of these problems, the infrastructures cannot function at the same time both efficiently and reliably. This presents a challenge of national importance that can be met within our own ESD Program. Wed, 01 May 2002 00:00:00 GMT https://hdl.handle.net/1721.1/102738 2002-05-01T00:00:00Z https://hdl.handle.net/1721.1/102737 Architecting/Designing Engineering Systems Using Real Options de Neufville, Richard Everyone concerned with engineering systems faces a common issue: How do we design systems to perform well in a constantly evolving and thus risky context? As professionals concerned with the system (rather than its individual pieces), this design issues predominantly relates to the overall configuration, the architecture of the system. This paper presents an approach to this fundamental issue. It suggests how we could architect flexible engineering systems that can evolve optimally to meet new challenges and opportunities. It suggests that the methods of “options analysis”-- that have revolutionized thinking about investments -- can provide a conceptual basis for defining optimal configurations. When these procedures are applied to design issues, they are generally known as "real options analysis". The fundamental result of "real options analysis" is the determination of the value of flexibility. It thus permits system designers and managers to decide which flexible design elements, that permit their system to evolve effectively over time, are worth their cost. It thus provides a clear rationale for when to design specific types of flexibility into the system. Wed, 01 May 2002 00:00:00 GMT https://hdl.handle.net/1721.1/102737 2002-05-01T00:00:00Z https://hdl.handle.net/1721.1/102736 The Evolving Role of Systems Analysis in Process and Methods in Large-Scale Public Socio-Technical Systems Marks, David H. The ESD definition of Large-Scale Socio-Technical Systems is large-scale and complex systems in which both human and non-human elements interact where the social and/or management dimensions tend to dominate. The word public has been added here to indicate that subset which are quasi public systems, i.e. the problems of public management of resources such as clean air and water or energy in which public policy is needed to drive and set the context for public investment and regulation which in turn influence private individual and corporate decisions. Systems analysis plays an important role in the formation of strategic policy for managing these resources. The paradigm of systems analysis as applied to large-scale open systems has not changed over the years. It is still the mantra of Problem Identification, Systems Modeling, Generation of Alternatives (Optimization), Evaluation and Implementation. However, both the process by which systems analysis is carried out, and the systems methods used in that process have evolved significantly and for the better. This paper deals with a description of these evolving methods and processes in the context of large-scale energy and environmental systems. In particular, pathways to the future in energy and environmental management are discussed as long-term system analysis problems. Systems Analysis process changes and methods changes, which have occurred and will need evolution in the future, are identified. Wed, 01 May 2002 00:00:00 GMT https://hdl.handle.net/1721.1/102736 2002-05-01T00:00:00Z https://hdl.handle.net/1721.1/102735 The Concept of a CLIOS Analysis Illustrated by the Mexico City Case Dodder, Rebecca The term CLIOS (Complex, Large-scale, Integrated, Open Systems) was conceived as way to capture the salient characteristics of a class of systems that are of growing interest to researchers, decisionmakers, policy makers and stakeholders. These systems range from an air traffic control system to the global climate system, and from Boston’s Big Dig to the eBay online trading system. We start by defining the primary characteristics of CLIOS. First, a system is complex when it is composed of a group of interrelated units (component and subsystems), for which the degree and nature of the relationships is imperfectly known – with varying directionality, magnitude and time-scales of interactions among the various subsystems. Second, CLIOS have impacts that are large in magnitude, and often long-lived and of large-scale geographical extent. Third, subsystems within CLIOS are integrated, closely coupled through feedback loops. Finally, by open we mean that CLIOS explicitly include social, political and economic aspects (Sussman, 2000a). Finally, with CLIOS we are as concerned with the complexity of the organizational and institutional parts of the systems as we are with the physical system. In fact, understanding the organizational and institutional structure and its interaction with the physical structure is one of the key potential values of a CLIOS analysis. Wed, 01 May 2002 00:00:00 GMT https://hdl.handle.net/1721.1/102735 2002-05-01T00:00:00Z https://hdl.handle.net/1721.1/102734 Collected Views on Complexity in Systems Sussman, Joseph M. The term complexity is used in many different ways in the systems domain. The different uses of this term may depend upon the kind of system being characterized, or perhaps the disciplinary perspective being brought to bear. The purpose of this paper is to gather and organize different views of complexity, as espoused by different authors. The purpose of the paper is not to make judgments among various complexity definitions, but rather to draw together the richness of various intellectual perspectives about this concept, in order to understand better how complexity relates to the concept of engineering systems. I have either quoted directly or done my best to properly paraphrase these ideas, apologizing for when I have done so incorrectly or in a misleading fashion. I hope that this paper will be useful as we begin to think through the field of engineering systems. The paper concludes with some short takes -- pungent observations on complexity by various scholars -- and some overarching questions for subsequent discussion. Wed, 01 May 2002 00:00:00 GMT https://hdl.handle.net/1721.1/102734 2002-05-01T00:00:00Z https://hdl.handle.net/1721.1/102733 Patterns of Product Development Interactions Eppinger, Steven D. Development of complex products and large systems is a highly interactive social process involving hundreds of people designing thousands of interrelated components and making millions of coupled decisions. Nevertheless, in the research summarized by this paper, we have created methods to study the development process, identify its underlying structures, and critique its operation. In this article, we introduce three views of product development complexity: a process view, a product view, and an organization view. We are able to learn about the complex social phenomenon of product development by studying the patterns of interaction across the decomposed elements within each view. We also compare the alignment of the interaction patterns between the product, process, and organization domains. We then propose metrics of product development complexity by studying and comparing these interaction patterns. Finally, we develop hypotheses regarding the patterns of product development interactions, which will be helpful to guide future research. Wed, 01 May 2002 00:00:00 GMT https://hdl.handle.net/1721.1/102733 2002-05-01T00:00:00Z https://hdl.handle.net/1721.1/102732 The Effect of e-Business on Supply Chain Strategy Simchi-Levi, David; Simchi-Levi, Edith Internet technology has forced companies to redefine their business models so as to improve the extended enterprise performance - this is popularly called e-business. The focus has been on improving the extended enterprise transactions including Intraorganizational, Business-to-Consumer (B2C) and Business-to-Business (B2B) transactions. This shift in corporate focus allowed a number of companies to employ a hybrid approach, the Push-Pull supply chain paradigm. In this article we review and analyze the evolution of supply chain strategies from the traditional Push to Pull and finally to the hybrid Push-Pull approach. The analysis motivates the development of a framework that allows companies to identify the appropriate supply chain strategy depending on product characteristics. Finally, we introduce new opportunities that contribute and support this supply chain paradigm. Wed, 01 May 2002 00:00:00 GMT https://hdl.handle.net/1721.1/102732 2002-05-01T00:00:00Z https://hdl.handle.net/1721.1/102731 Physical Limits to Modularity Whitney, Daniel E. Architecture, specifically the definition of modules and their interconnections, is a central concern of engineering systems theory. The freedom to choose modules is often taken for granted as an essential design decision. However, physical phenomena intervene in many cases, with the result that 1) designers do not have freedom to choose the modules, or 2) that they will prefer not to subdivide their system into as small units as is possible. A distinction that separates systems with module freedom from those without seems to be the absolute level of power needed to operate the system. VLSI electronics exemplify the former while mechanical items like jet engines are examples of the latter. It has even been argued that the modularity of VLSI should be extended to mechanical systems. This paper argues that there are fundamental reasons, that is, reasons based on natural phenomena, that keep mechanical systems from approaching the ideal modularity of VLSI. The argument is accompanied by examples. Wed, 01 May 2002 00:00:00 GMT https://hdl.handle.net/1721.1/102731 2002-05-01T00:00:00Z https://hdl.handle.net/1721.1/102730 An Attempt at Complex System Classification Magee, Christopher L.; de Weck, Olivier L. This paper searches for a useful taxonomy or classification scheme for complex Systems. There are two aspects to this problem: 1) distinguishing between Engineering Systems of interest to ESD (ES) and other Systems, and 2) differentiating among Engineering Systems. The first of these has been approached through general interaction with other ESD faculty and use of the ESD definitions. This analysis leads to a proposed specific set of ES which are human designed, have high technical and human complexity and are real, open, dynamic, have hybrid system states and have both autonomous and human-in–the loop subsystems or elements. Wed, 01 May 2002 00:00:00 GMT https://hdl.handle.net/1721.1/102730 2002-05-01T00:00:00Z https://hdl.handle.net/1721.1/102729 Incorporating Uncertainty Into Conceptual Design of Space System Architectures Hastings, Daniel E.; Weigel, Annalisa; Walton, Myles A. The environment in which space systems are developed and operated can be classified as nothing less than dynamic. However, it is clear that the methods and tools relied on in conceptual design are based on static assumptions and leave little room for anything more than snapshots of the product and its environment. This paper introduces an approach to challenge that model and instead quantify and compare space system architectures around the central theme of uncertainty, with emphasis on policy uncertainty, as well as, technical and market uncertainty. Two cases of implementation are presented and three generalized principles are proposed that flow from the analysis: 1) engineering systems must be designed with uncertainty as one of the central organizing principles, 2) since engineering systems have management and social dimensions and thus involve human interactions, there is an irreducible uncertainty associated with these dimensions that will affect the design of the system, and 3) uncertainty in use may allow the engineering system to satisfy quite different missions from the original one intended. Wed, 01 May 2002 00:00:00 GMT https://hdl.handle.net/1721.1/102729 2002-05-01T00:00:00Z https://hdl.handle.net/1721.1/102728 Global Comparison Aggregation Services Zhu, Hongwei; Madnick, Stuart E.; Siegel, Michael D. Web aggregation has been available regionally for several years, but this service has not been offered globally. As an example, using multiple regional comparison aggregators, we analyze the global prices for a Sony camcorder, which differ by more than three times. We further explain that lack of global comparison aggregation services partially contribute to such huge price dispersion. We also discuss difficulties encountered in the manual integration of global web sources. Motivated by this example, we propose a context mediation architecture for global aggregation to address semantic disparities of global information sources. Global aggregation services can bring efficiency to the global market and can be useful for market research and other business uses. Sun, 01 Dec 2002 00:00:00 GMT https://hdl.handle.net/1721.1/102728 2002-12-01T00:00:00Z https://hdl.handle.net/1721.1/102727 The Interplay of Web Aggregation and Regulation Zhu, Hongwei; Madnick, Stuart E.; Siegel, Michael D. The development of web technology has led to the emergence of web aggregation, a service that collects existing web data and turns them into more useful information. We review the development of both comparison and relationship aggregation and discuss their impacts on various stakeholders. The aggregator's capability of transparently extracting web data has raised challenging issues in database and privacy protection. Consequently, new regulations are introduced or being proposed. We analyze the interactions between aggregation and related policies and provide our insights about the implications of new policies on the development of web aggregation. Fri, 01 Nov 2002 00:00:00 GMT https://hdl.handle.net/1721.1/102727 2002-11-01T00:00:00Z https://hdl.handle.net/1721.1/102726 Evaluating Accident Models Using Recent Aerospace Accidents, Part 1: Event-Based Models Leveson, Nancy G. This report was inspired by a graduate reading group that was held at MIT during the fall semester, 2000. Each week, 20-25 graduate students and 3-4 faculty examined a different aerospace accident report (about evenly divided between aeronautics and astronautics). Our goal was to look at recent accidents (all but one of the accidents involved software) and determine how well traditional accident models fit these accidents in modern complex systems and whether there are common systemic factors that can be identified. The accident reports examined involved the Ariane 5; the Space Shuttle Challenger; the Mars Climate Orbiter; the Mars Polar Lander; the Titan IV/Milstar; an American Airlines B-757 near Cali, Colombia; A Lufthansa A320 at Warsaw; and a China Airlines A320 at Nagoya, Japan. Fri, 01 Jun 2001 00:00:00 GMT https://hdl.handle.net/1721.1/102726 2001-06-01T00:00:00Z https://hdl.handle.net/1721.1/102725 ESD Internal Conference Extended Abstracts ESD Colloquium Committee This working paper contains the extended abstracts received to date for the ESD Colloquium to be held on May 29 and 30, 2002. A proceeding of the complete papers are planned to be published in advance of the colloquium. Fri, 01 Mar 2002 00:00:00 GMT https://hdl.handle.net/1721.1/102725 2002-03-01T00:00:00Z https://hdl.handle.net/1721.1/102724 Do-It-Right-Fisrt-Time (DRFT) Approach to DSF Restructuring Yassine, Ali A.; Whitney, Daniel E.; Lavine, Jerry; Zambito, Tony In this paper, we argue, using two real-world applications from the automotive industry, that the biggest benefit of a Design Structure Matrix (DSM) model may come not from resequencing and partitioning, but rather from “rewiring” the process/blocks. By “rewiring” we mean redefining relationships among elements and/or inserting new elements into the matrix. This requires intimate understanding of the process and cannot be done with application of context-free partitioning algorithms. The Do-it-Right-First-Time (DRFT) approach to DSM restructuring is another way to look at a DSM by inspecting the sources of iteration within a block and reversing it through inserting a DRFT activity at the beginning of the block. In other words, we reverse the traditional Design-Build-Test “Cycle” into a DRFT-Design-Build “Sequence”. That is, the "wiring diagram" of a process or system overpowers the behavior of the individual nodes, so changing the system requires changing the wiring. Sat, 01 Sep 2001 00:00:00 GMT https://hdl.handle.net/1721.1/102724 2001-09-01T00:00:00Z https://hdl.handle.net/1721.1/102723 Designing a Requirement Driven Product Development Process Dong, Qi; Whitney, Daniel E. This paper presents a technique to obtain a Design Structure Matrix (DSM) from a Design Matrix (DM). This technique enables us to obtain the design information flow pattern at early stage of the design, and apply the DSM system analysis and management techniques at the time when the most important decisions about the system and the design are made. The validity of this method is proven using a case study on the design integration process of an electrostatic chuck used in semiconductor wafer processing. The algorithm underlying this technique is also proven logically and mathematically to be valid. Sat, 01 Sep 2001 00:00:00 GMT https://hdl.handle.net/1721.1/102723 2001-09-01T00:00:00Z https://hdl.handle.net/1721.1/102722 Improving the Software Upgrade Value Stream Ippolito, Brian; Murman, Earll M. This paper reports findings from a two-year study to identify Lean practices for deriving software requirements from aerospace system level requirements, with a goal towards improving the software upgrade value stream. The study was undertaken as part of the MIT Lean Aerospace Initiative. Three detailed case studies and 128 surveys collected from ten "successful" mission critical aerospace software upgrade programs support seven major findings. Sat, 01 Dec 2001 00:00:00 GMT https://hdl.handle.net/1721.1/102722 2001-12-01T00:00:00Z https://hdl.handle.net/1721.1/102721 ESD Terms and Definitions (Version 12) Allen, Thomas J.; Moses, Joel; Hastings, Daniel E.; Lloyd, Seth; Little, John D. C.; McGowan, Don; Magee, Christopher L.; Moavenzadeh, Fred; Nightingale, Deborah J.; Roos, Daniel; Whitney, Dan Basic terms related to engineering systems Mon, 01 Oct 2001 00:00:00 GMT https://hdl.handle.net/1721.1/102721 2001-10-01T00:00:00Z https://hdl.handle.net/1721.1/102720 Three Perspectives on Modularity – A Literature Review of a Product Concept for Assembled Hardware Products Fixson, Sebastian K. In recent years, modularity as a design strategy has received renewed interest. The term modularity, however, is often used to describe phenomena that are similar yet slightly different, for different products, and in different industries and contexts. Therefore, it is unclear whether there is a way to operationalize the concept of modularity across these different uses. This paper reviews the concepts of modularity used in the literature representing different thought worlds (engineering and management) and different occupations (academia and industry). Mon, 01 Oct 2001 00:00:00 GMT https://hdl.handle.net/1721.1/102720 2001-10-01T00:00:00Z https://hdl.handle.net/1721.1/102719 Managing the Global knowledge-creation Network: A Sense Making Perspective Mohrman, Susan Albers; Klein, Janice A.; Finegold, David We have entered the era of the knowledge economy, a period when knowledge has replaced natural resources and capital as the most important economic resource. Increasingly, corporations are reaching out globally to secure the best talent available at the most reasonable cost to serve world-wide markets. Wed, 01 Aug 2001 00:00:00 GMT https://hdl.handle.net/1721.1/102719 2001-08-01T00:00:00Z https://hdl.handle.net/1721.1/102718 Extracting the Essence of Flexibility in System Design Saleh, Joseph H.; Hastings, Daniel E.; Newman, Dava The modest purpose of this paper is to review the concept of flexibility as discussed in various fields of investigations, and to extract its characteristic features. In order to discuss any subject matter clearly, it is necessary to begin with a clear set of definitions. Indeed much can be gained through careful and consistent definitions of terms alone. Flexibility however is a word rich with ambiguity. While it is being increasingly used in various fields, few attempts have been made to formally define, quantify, and propose ways for achieving flexibility. This paper proposes to fill in part this gap by synthesizing a clear and consistent definition of flexibility. It will do so by reviewing the usage of the term in various fields of inquiries, and show that it is indeed possible to clearly and unambiguously characterize flexibility, and to disentangle it from closely related concepts. Wed, 01 Aug 2001 00:00:00 GMT https://hdl.handle.net/1721.1/102718 2001-08-01T00:00:00Z https://hdl.handle.net/1721.1/102717 Initial Top-Level Characterization of the Air Force Sustainment System Bozdogan, Kirk; Sussman, Joseph M.; Allen, Thomas J.; Harris, Wesley L. This draft white paper presents an initial top-level characterization of the Air Force sustainment system. The first part of the paper gives an overview of the proposed conceptual framework for system characterization. The second part presents an initial top-level characterization of the system, by using this framework, and offers some preliminary suggestions or recommendations. Finally, next steps in the research process are outlined, placing the paper in the larger context of the task on system characterization and transformation. Sun, 01 Apr 2001 00:00:00 GMT https://hdl.handle.net/1721.1/102717 2001-04-01T00:00:00Z https://hdl.handle.net/1721.1/102716 Aircraft System and Product Development: Teaching the Conceptual Phase Murman, Earll M.; Hansman, Robert J., Jr.; Clarke, John-Paul This paper reports the first offering of a graduate level subject covering the conceptual phase of aircraft product development. The output of the conceptual phase is a system level specification that usually serves as the input for a traditional undergraduate capstone subject on aircraft design. Of critical importance in the conceptual phase is addressing the business case for the candidate product. The conceptual phase spans a much wider range of topics than the technical issues which dominate preliminary design. These include user needs, investment and business requirements, market analysis, operational issues, exogenous constraints (certification, regulation, political, etc.), as well as engineering and manufacturing requirements. Students in the subject were required to Prepare for the Board of Directors of a large aerospace company a compelling business case and specification for a large jet transport product. Three student teams produced original responses to the challenge and have reported their findings in a companion AIAA paper. This paper addresses the pedagogical approaches and outcomes. These encompass the use of distance learning technology and techniques for several off-campus practicing engineering students. Overall, the outcome was very gratifying. The class will be offered in the spring of 2001, focusing on a supersonic business jet. Mon, 01 Jan 2001 00:00:00 GMT https://hdl.handle.net/1721.1/102716 2001-01-01T00:00:00Z https://hdl.handle.net/1721.1/102715 Toward a New Technology and Policy Program (TPP) Curriculum Dodder, Rebecca; Hastings, Daniel E.; Kochan, Thomas Anton; Lester, Richard K.; Marks, David H.; Oye, Kenneth A.; Sussman, Joseph M.; Steinberg, Arthur; Tabors, Richard D. The mission of the MIT Technology and Policy Program (TPP) is: “Provide an integrative education to scientists and engineers who wish to lead in the development and implementation of responsible strategies and policies for exploitation of technology for the benefit of their communities” (Hastings, 2000). Embedded in the TPP mission statement are several educational requirements: (1) a comprehensive and diverse set of solid analytical skills needed to develop and assess strategies and policies, (2) the flexibility to manage the conflicting interests and values that are present at all stages of the policy process, and (3) the ability to provide leadership at each stage in the policy process. With these concepts in mind, the TPP Curriculum Development Committee will work to place TPP at the forefront of educating the “leaders (researchers and practitioners) of the fields of technology and policy studies” (Hastings, 2000). Mon, 01 Jan 2001 00:00:00 GMT https://hdl.handle.net/1721.1/102715 2001-01-01T00:00:00Z https://hdl.handle.net/1721.1/102701 Surviving and Thriving in the New World of Web Aggregators Madnick, Stuart E.; Siegel, Michael D.; Frontini, Mary Alice; Khemka, Saraubh; Chan, Steven; Pan, Howard This paper examines the development of aggregators, entities that collect information from a wide range of sources, with or without prior arrangements, and add value through post-aggregation services. New Web-page extraction tools, context sensitive mediators, and agent technologies have greatly reduced the barriers to constructing aggregators. We predict that aggregators will soon emerge in industries where they were not formerly present. Through studying over a hundred existing and emerging aggregators, we present a model for understanding the aggregator's strategic interaction with the incumbent. We also suggest different business models as possible aggregator entry points into an industry and describe their impact. Sun, 01 Oct 2000 00:00:00 GMT https://hdl.handle.net/1721.1/102701 2000-10-01T00:00:00Z https://hdl.handle.net/1721.1/102700 Challenges in the Better, Faster, Cheaper Era of Aeronautical Design, Engineering and Manufacturing Murman, Earll M.; Walton, Myles; Rebentisch, Eric “Better, Faster, Cheaper” (BFC) emerged in the 1990s as a new paradigm for aerospace products. In this paper, we examine some of the underlying reasons for BFC and offer some thoughts to help frame the thinking and action of aerospace industry professionals in this new era. Examination of literature on industrial innovation indicates that aeronautical products have evolved to a “dominant design” and entered the “specific phase” of their product life cycle. Innovation in this phase centers on: incremental product improvement, especially for productivity and quality; process technology; technological innovations that offer superior substitutes. The first two of these are aligned with BFC objectives. https://hdl.handle.net/1721.1/102700 https://hdl.handle.net/1721.1/97647 Survey Design to Unravel Freight Transportation Demand of Establishments in Cities Lee, Yin Jin; Blanco, Edgar E.; D'Ambrosio, Lisa A.; Zegras, P. Christopher Freight transportation serves the vital role of fulfilling the goods demand of residents in cities, yet little is known about the mechanisms that generate freight movements and their impact on traffic. Even though technology may allow us to better trace real-time movements, establishment surveys are still important to collect data on strategic and tactical freight transportation decisions. Leveraging state-of-art knowledge, a survey was specifically designed to investigate freight travel demand. This paper shows the preparation, execution and data processing of a survey on establishments in Singapore. Analysis of the survey data allows us to explain variations in delivery, such as, the types of supplier, the size and frequency of goods deliveries, and the timing of deliveries. Fri, 22 May 2015 00:00:00 GMT https://hdl.handle.net/1721.1/97647 2015-05-22T00:00:00Z https://hdl.handle.net/1721.1/97646 Characteristics and Enablers of Transparency in Product Development Organizations Shaffer, Ryan M.; Olechowski, Alison Louise; Seering, Warren; Ben-Daya, Mohammad Risks in product development lead to schedule and cost overruns and poor product quality. While many risk management frameworks have been published and research on specific practices has been conducted, little is understood of key characteristics of successful risk management in product development and how they manifest in real development projects. This research consists of two phases. The first phase is a survey on 171 best practices in risk management. Analysis of over 200 responses from industry practitioners identified transparency as a key characteristic of successful risk management in product development. Due to the limited exploration of the concept of transparency in the literature, the second phase of this work consisted of a qualitative investigation of transparency through interviews with 15 industry practitioners. Analysis of the interview results suggests a hierarchical structure which decomposes transparency into several characteristics and identifies enablers for each of these characteristics. We propose that transparency can be a valuable lever for product developers and managers. Future work is needed to validate the generalizability of the observations provided. Sun, 04 Jan 2015 00:00:00 GMT https://hdl.handle.net/1721.1/97646 2015-01-04T00:00:00Z https://hdl.handle.net/1721.1/97645 Modeling the Cost of International Trade in Global Supply Chains Blanco, Edgar E.; Ponce Cueto, Eva Maria In a global economy, international trade plays an important role of the economic development. This is especially relevant in emerging markets, where trade could contribute significantly to the economic growth of the country. Many studies have pointed out the relationship between logistics performance and the volume of bilateral trade. Limão and Venables (2001) analyze transport costs, Hummels (2001) analyzes transport time and Hausman et al. (2013) evaluate the impact of specific improvements in logistics performance in terms of time, cost and reliability (variability in time) on increased trade. International Trade ads complexity as goods move across borders where are subject to import and export activities that increase lead times and variability on financial and physical flows (e.g. more documents per trade transaction, more signatures per trade transaction, export clearance, and customs inspection). Also, these global supply chains often involve more actors and agencies that support the trade process such as inspection agencies and custom brokers. Surveys aimed at calculating these costs suggest that they may range from 2% to 15% of the value of traded goods. This paper provides a general framework to model the impact of international trade of a global supply chain. A cost function is proposed for the buyer, the seller and the upstream suppliers that explicitly refers to the additional elements of international trade. The model is applied to compare the impact of different Incoterms rules (see section 3.2.1) in an International Trade taking into account the total cost of the supply chain Blanco, E.E. and Ponce-Cueto, E. – MIT Center for Transportation & Logistics – March 2015 2 for the main actors, including the buyer (importer) and the seller (exporter). The paper is organized as follows. Section 2 includes a succinct literature review of relevant papers in global trade management, and more specifically a review of those papers that focus on the total cost in global supply chains. Section 3 defines the global supply chain under study and presents the key events in a global trade. A total global trade function is formulated in Section 4, one function cost for buyers and another for upstream sellers. In section 5 the supply chain costs under various trade scenarios are presented and a numerical example is developed in order to illustrate the applicability of the model. Discussion and conclusion are included in section 6. Sun, 01 Mar 2015 00:00:00 GMT https://hdl.handle.net/1721.1/97645 2015-03-01T00:00:00Z https://hdl.handle.net/1721.1/97644 Analysis of Capacity Pricing and Allocation Mechanisms in Shared Railway Systems: Lessons for the Northeast Corridor Pena-Alcaraz, Maite; Sussman, Joseph M.; Webster, Mort Recently, governments have started promoting the use of shared railway systems as a way to take advantage of the existing capital-intensive railway infrastructure. Until 1988, all major railways both managed the infrastructure and operated the trains. In contrast, in shared railway systems, multiple train operators utilize the same infrastructure. Such systems can achieve high utilization, but also require coordination between the infrastructure manager and the train operators. Such coordination, in turn, requires capacity planning and regulation that determines which trains can access the infrastructure at each time, capacity allocation, and the access price they need to pay, capacity pricing. The need to establish capacity pricing and allocation mechanisms in the railway system is relatively new and the comparative performance of alternative mechanisms to price and allocate capacity is still a matter of study. This paper proposes a framework to analyze the performance of shared railway systems under alternative capacity pricing and allocation mechanisms. The paper focuses on how the introduction of price-based and capacity-based mechanisms affect the train operators’ ability to access the infrastructure capacity in the context of the Northeast Corridor in the US. The results of this paper suggest that there are trade-offs associated with each mechanism and none of them is superior to the other on all dimensions. As a result, Northeast Corridor stakeholders should carefully analyze the implications of alternative pricing and allocation mechanisms before locking the system into one of them. Sun, 01 Mar 2015 00:00:00 GMT https://hdl.handle.net/1721.1/97644 2015-03-01T00:00:00Z https://hdl.handle.net/1721.1/97643 Eco-Growth: A Framework for Sustainable Growth Blanco, Edgar E.; Sheffi, Yossi Growth is imperative for corporate success and yet the environmental impact of this growth is not sustainable. In this paper we offer a framework for thinking about the stages of tackling the environmental sustainability challenge. It ranges from eco-efficiency, which includes initiatives that reduce costs while reducing environmental footprint; eco-alignment, including initiatives requiring cooperation with suppliers and customers; eco-innovation, which includes initiatives based on innovative products and processes; and eco-growth which includes initiatives contributing to the company’s growth, combining all the others. The second part of the paper offers a framework for analyzing the trade-off between shareholders objectives and sustainability objectives. The framework is based on the concept of the efficiency frontier and is used to tie to the four proposed stages of tackling environmental sustainable growth. Thu, 01 Jan 2015 00:00:00 GMT https://hdl.handle.net/1721.1/97643 2015-01-01T00:00:00Z https://hdl.handle.net/1721.1/97642 A Survey of Methods for Data Inclusion in System Dynamics Models Houghton, James P.; Siegel, Michael D.; Wirsch, Anton; Moulton, Allen; Madnick, Stuart E.; Goldsmith, Daniel K. In 1980, Jay Forrester enumerated three types of data needed to develop the structure and decision rules in models: numerical, written and mental data, in increasing order of importance. While this prioritization is appropriate, it is numerical data that has experienced the most development in the 25 years since Forester made his enumeration. In this paper, we’ll focus on how numerical data can be incorporated into models when written and mental data are known, and survey the techniques for doing so. Thu, 01 May 2014 00:00:00 GMT https://hdl.handle.net/1721.1/97642 2014-05-01T00:00:00Z