Achieving resiliency in major defense programs through nonfunctional attributes

Abstract

This article examines how the ilities, or nonfunctional attributes, help to understand the concept of resiliency in engineered systems. For engineered systems, resiliency describes the ability of a system to react to and return to full function after an interruption to system operation. The literature on resiliency of engineered systems defines resiliency in both the context of mission and platform resiliency; however, it leaves an opportunity to research how to understand, manage, and achieve resiliency. This work proposes an application of the systems engineering ilities to resiliency to understand how systems engineers can account for resiliency in the design process and incorporate resiliency into systems. Quality, robustness, and agility assist in understanding the components of resiliency and the ilities of repairability, extensibility, flexibility, adaptability, and versatility provide means for systems to achieve resiliency. This article applies this framework to examine two cases of DoD systems, the B‐52 bomber and the F‐117 stealth fighter. These two examples demonstrate how nonfunctional attributes enable engineered systems to achieve resiliency and help to better understand the concept of resiliency in engineered systems.

Analysis of Resilience Situations for Complex Engineered Systems – the Resilience Holon

“…For example. Enos [49] relates the ilities to resiliency; adaptability, extensibility, flexibility, repairability, and versatility are identified as achieving resiliency for engineered systems in defense programs. The resilience profile does not include ilities directly, but some of the capacities are aligned with ilities.…”

“…R6 Recoverability: (Restorative capacity) Recoverability is the "ability of the system to recover in a timely manner" [14], also defined as the restorative capability [54]. Similarly, repairability is "the ability to be returned to the original state of function when some function is lost" [49]. Of concern are the amount of time needed to restore functionality, and the need for replacement of parts of a system to achieve restoration.…”