Engineering of complex systems: The impact of systems engineering at NASA

The "true" impact or value of systems engineering to an organization unfortunately appears not to have been well-studied and understood. The principles of systems engineering are highly encouraged by NASA at all levels, and most practitioners, both internal and external to NASA, intuitively "believe" it adds some value to the development of complex systems by producing them faster, better and cheaper.; This research, in trying to fill a gap that exists in the systems engineering literature, analyzes data collected within NASA and other sources external to NASA (INCOSE) for comparisons. Analyses involving a number of case studies performed on selected NASA projects are presented to draw attention to the impact systems engineering had or could have had on these projects.; This research clearly shows that systems engineering does add value to projects within and outside NASA. The research results further demonstrate that systems engineering has been beneficial not only to NASA but also to organizations within which INCOSE members work. It was determined, however, that systems engineering does not operate in a vacuum and may not always guarantee success through mere application.; During this research, it was discovered that the lack of or inadequate application of systems engineering in the development of complex systems may result in cost overruns, poor technical performance, project delays, and in some cases unmitigated risk with disastrous consequences including the loss of life and property. How much is saved (in terms of cost, schedule) or improved (in terms of technical performance) as a result of its implementation may never be known precisely, but by indirectly measuring its value or impact on a project, percentages of project budget spent on systems engineering activities and any schedule reductions or performance enhancements realized could be determined. According to this research, systems engineering is not a waste of time and resources; in most cases, it is likely to produce some positive impact or value in terms of cost, schedule, technical performance, and risk when applied.; The stage in a project's life cycle in which systems engineering is introduced may determine the potential value to be realized by the project. The generation of systems engineering documents is not an indicator of proper execution or performance of systems engineering activities. Projects, as this research shows, are selective in documents they generate.; Completion or attendance of job-sponsored systems engineering training programs has little or no effect on NASA engineers and their INCOSE counterparts. This research also uncovered some nontechnical (political and cultural preconceptions or alignments) issues that, when not properly addressed, may impact or impede the value derived from systems engineering.; This dissertation also examined the satisfaction with the systems engineering process and the willingness of participants from the two groups studied (NASA and INCOSE) to use it on future projects.; The approach used in this study may provide a tool for evaluating the benefits or impact of systems engineering on a project. The research also emphasizes the benefits and relationships among systems engineering, cost, technical performance, schedule, and risks in its analysis of selected NASA projects.