Towards a Prescriptive Semantic Basis for Change-type Ilities

The concept of incorporating “ilities” into systems seems a self-evidently good idea, as expressed by both written and spoken positions by technical and political leaders. Indeed, incorporating lifecycle properties such as flexibility, adaptability, and recently affordability and resilience, into systems is touted as the solution to modern day's ever increasing complexity, schedule and budget pressures, and the need for finding sustainable solutions. While expressing desires for ilities seems straightforward, tracing these desires to verifiable system instantiations remains ambiguous at best. This paper describes the semantic challenge underlying the concept of a coherent set of system properties, a sampling of various efforts to ascribe meaning to particular ilities, and proposes a prescriptive 20 category semantic basis for specifying a set of ilities, while avoiding the assertion of new definitions. The intention for this first pass prescriptive semantic basis is to begin a structured approach for exploring the existence of one or more semantic fields, which together form a coherent semantic framework for tracing desired ilities into verifiable system requirements and specifications. Preliminary results indicate that at least three semantic fields exist within the larger set of system lifecycle properties including change-type, architecture-type, and new ability-type ilities.