Cost estimation of human systems integration

Abstract

Human Systems Integration (HSI) is the interdisciplinary technical and management processes for integrating human considerations within and across all system elements. The goal of this research is to develop a better understanding of how the costs of doing HSI work within a program can be estimated. The research is divided into two parts. In the first part, problem formulation, literature from several relevant domains is first reviewed. Next a descriptive case study is conducted on the development of the Pratt and Whitney F 119 engine. It examines activities done to support HSI up to engineering and manufacturing development and concludes that, among other factors, HSI in requirements are a major driver of effort. This conclusion leads to work on the integration of HSI into the counting of requirements for an existing systems engineering cost model. In the second part of the research, implementation and validation, two workshops are conducted to assess how HSI considerations are addressed in real-world requirements engineering. The first workshop tests existing requirements counting guidelines, identifies weakness, and suggests improvement. The second workshop applies the Wideband Delphi method to generate consensus between stakeholders in order to deliver a quantitative estimate of HSI effort. The workshop also demonstrates that stakeholders perceive functional and nonfunctional requirements as driving effort in similar ways, a conclusion that challenges a widely-held belief that nonfunctional requirements are less significant than functional ones. The research done in the case study and workshops results in improvements to the existing systems engineering cost model, and an application of the model is presented. Policy considerations are discussed. The integration of the HSI into the model represents a significant step toward being better able to plan HSI effort in acquisition programs.