Two Empirical Tests of Design Principles for Survivable System Architecture

Survivability, the ability of a system to minimize the impact of a finite-duration disturbance on value delivery, is increasingly recognized beyond military contexts as an enabler for maintaining system performance in the presence of dynamic disturbance environments. This paper attempts to validate a preliminary set of twelve general design principles for survivability through two empirical tests. Survivability features of the A-10A “Warthog” combat aircraft and UH-60A Blackhawk helicopter, two systems designed for reduced vulnerability, are inductively traced to an existing set of principles. Seven unique insights are derived from the analysis, and the design principles are revised to reflect the lessons learned. A new set of seventeen design principles are formalized: six aimed at reducing susceptibility and eleven aimed at reducing vulnerability. The paper concludes with propositions for future work for developing a theory of survivable system architecture and a discussion of the importance of empiricism in systems engineering.