Style-Based Architectural Reconfigurations

We introduce Architectural Design Rewriting (ADR), an approach to deal with the design of reconfigurable software architectures. The key features we promote are: (i) rule-based approach (over graphs); (ii) hierarchical design; (iii) algebraic presentation; and (iv) inductivelydefined reconfigurations. Architectures are suitably modeled by graphs whose edges and nodes respectively represent components and connection ports. Architectures are designed hierarchically by a set of edge replacement rules that fix the architectural style. Depending on their reading, productions allow: (i) top-down design by refinement, (ii) bottomup typing of actual architectures, and (iii) well-formed composition of architectures. The key idea is to encode style proofs as terms and to exploit such information at run-time for guiding reconfigurations. The main advantages of ADR are that: (i) instead of reasoning on flat architectures, ADR specifications provide a convenient hierarchical structure, by exploiting the architectural classes introduced by the style, (ii) complex reconfiguration schemes can be defined inductively, and (iii) stylepreservation is guaranteed.