Reconciling software requirements and architectures: the CBSP approach

Little guidance and few methods are available to refine a set of software requirements into an architecture satisfying those requirements. Part of the challenge stems from the fact that requirements and architectures leverage different terms and concepts to capture the artifacts relevant to each. We present CBSP (Component-Bus-System- Property), a lightweight approach intended to provide a systematic way of reconciling requirements and architectures. CBSP leverages a simple set of architectural concepts (components, connectors, overall systems, and their properties) to recast the requirements in a way that facilitates their straightforward mapping to architectures. Furthermore, the approach allows us to capture and maintain arbitrarily complex relationships between requirements and architectural artifacts, as well as across different CBSP artifacts. We have extensively applied CBSP within the context of particular requirements and architecture definition techniques, EasyWinWin and C2. We leverage that experience to demonstrate the CBSP method and tool support using a large-scale example that highlights the transition from an EasyWinWin requirements negotiation into a C2-style architectural model.