Architectural stability and evolution measurement for software reuse

Software reuse has been established as a development practice due to several benefits like development cost reduction. However, successful reuse depends on several factors, including high level attributes of the reused software. Architectural stability is an important factor for software reuse, either during the reusable asset selection or library upgrades. In this paper, we introduce two sets of metrics that measure the architectural stability and the evolution of software projects in the context of software reuse. The first set of architectural stability metrics measures the degree of consistency between consecutive versions of the same system and considers the common architectural elements. The second set of architectural evolution metrics quantifies the architectural evolution between consecutive versions of the same system and considers the newly introduced architectural elements, as well as how they interact with the remaining elements of the system. Finally, we present the application of the proposed metrics to two categories of software projects: (1) projects developed for reuse and (2) projects that were not originally intended for reuse.