Identifying How Nonfunctional Attributes Affect a System's Lifecycle

Engineered systems often operate well beyond their planned retirement date due to a variety of factors from affordability to performance. This paper presents a grounded theory approach to identifying the nonfunctional attributes that separate Department of Defense (DoD) systems that the DoD extends beyond retirement and those that it chooses to retire. The systems engineering ilities, nonfunctional attributes, serve as a means to code textual data on these systems to develop and validate the grounded theory. It examines a total of fourteen DoD systems to first develop an initial grounded theory and then validate the grounded theory that the attributes of extensibility, flexibility, interoperability, robustness, and versatility are more common in extended DoD systems. The data indicates that these attributes differentiate the two groups of systems, retired and extended, at a statistically significant level and the decision to retire a DoD system is dependent on the nonfunctional attributes of these systems. By understanding what system attributes make a system more likely to be extended, engineering managers can better manage a system throughout its lifecycle. Finally, it presents potential future work to include the expansion of the grounded theory application to other systems and disruptive technologies.