ABC: supporting software architectures in the whole lifecycle

How to compose prefabricated components is a key issue in component-based reuse. Research on software architecture (SA) and component based software development (CBSD) provides two hopeful solutions from different perspectives. SA provides a top-down approach to realizing component-based reuse, but doesn´t pay enough attention to the refinement and implementation of the architectural descriptions, thus not fully able to automate the transformation or composition to form an executable application. CBSD provides a bottom-up way by using existing middleware infrastructures, but this technology is not able to guide systematically the CBSD process, especially the component composition at higher abstract levels. Naturally, a promising solution is to combine the above two approaches to realize component-based reuse. From the above discussion, we argue that SA should play a centric role in the whole software lifecycle, that is, SA description is used as the blueprint and middleware technology as the runtime scaffold for component composition, maintenance and evolution. To demonstrate the philosophy, we propose a software reuse methodology, which is called ABC (Architecture Based Component Composition) (Mei et al., 2001). ABC introduces software architectures into each phase of software life cycle, takes SA as the blueprint of system development, shortens the distance between high-level design and implementation by supporting tools and mapping mechanisms, realizes the automated system composition and deployment on runtime component operating platforms, and makes architecture available at runtime for software maintenance and evolution.