Process-Oriented Metrics for Software Architecture Changeability

Changeability is an important non-functional requirement (NFR) for software systems and evaluation of software changeability will be helpful for software practitioners. Briefly stated, changeability is the ease with which software system can be changed or modified. It is widely accepted that NFRs such as changeability should be incorporated in the architectural stage of software development itself to maximize the changeability of the system. The paper proposes the framework called the Process-Oriented Metrics for Software Architecture Changeability (POMSAC) that helps generate changeability metrics for software architectures during the process of architecture development. POMSAC helps generate intuitive metrics for changeability and traces the metrics to the requirements for which the architecture exists in the first place. We present an example metrification scheme – a single-value (SV) metrification schemethat meets the guidelines of POMSAC, and apply the SV scheme to a practical banking system. This application illustrates the advantages of the processoriented approach.