Measuring space systems flexibility : a comprehensive six-element framework

Abstract

Space systems are extremely delicate and costly engineering artifacts that take a long time to design, manufacture, and launch into space and after they are launched, there is limited access to them. Millions of dollars of space systems assets lost annually, when the space system has failed to meet new market conditions, cannot adapt to new applications, its technology becomes obsolete or when it cannot cope with changes in the environment it operates in. Some senior leaders have called for more flexible space systems. The existence of flexibility can help it adapt itself to the change at hand, or even take advantage of new possibilities while in space. Yet in the absence of a practical way to measure its value, most decision-makers overlook its implementation in their space systems. Although the literature is not lacking in number of flexibility measures, there is a void in articulating a unified and comprehensive framework for measuring the multiple aspects of flexibility in space systems. This research is an effort to provide such a framework based on the common fundamental elements that define the nature of flexibility in space systems and other engineering systems. Through the extraction of common elements of flexibility from 25 major papers in the field of space systems flexibility,

(cont.) more than 60 papers in the field of manufacturing flexibility and 43 papers in the field of systems engineering, this dissertation identified uncertainty, time window of change, system boundary, response to change, the system aspect to which flexibility is applied, and access to the system as the six key elements that affect the value flexibility. Based on the six elements, the 6E Flexibility Framework was proposed as a twelve-step framework that can guide decision-makers in assessing the value of flexibility in their system. The framework was then applied to four case studies dealing with a variety of space systems (commercial, military and scientific) with monetary and non-monetary value delivery, at different scales (satellite level, fleet level), different time windows of change and with regards to different aspects of flexibility (life extension, instrument upgrade, capacity expansion) facing different kinds of uncertainty (technological change and market uncertainty). The case studies demonstrated the ability of such a framework to provide decision-makers with the information necessary to integrate flexibility in their design and operational decisions and showed that the 6E Flexibility framework could be applied across different aspects of a system easily, capturing the impact of flexibility on design of and decision-making for space systems.