Composition Of Style-Based Software Architectures From Architectural Primitives

The codification of software architectural decisions made to address recurring software development challenges results in architectural styles. The Alfa framework provides a small set of architectural primitives for systematically specifying styles and style-based architectures for networkbased systems. In this paper, we formalize Alfa’s primitives in a compositional theory of styles and software architectures. Formalization of this theory has helped us discover one missing primitive in Alfa. Moreover, this theory establishes a refinement relation between styles and architectures along five dimensions: structure, behavior, interaction, data, and topology. Finally, this approach supports heterogeneous architectural composition, i.e., using multiple styles in a single architecture. We illustrate our approach using the software architecture of a networkbased system that employs three different styles: pipeline, event-based integration, and client/server.