BPEL or Business Process Execution Language is so far the most important standard language for effective composition of Web services. However, like most available process orchestration engines, BPEL does not provide automated support for reacting according to many changes that are likely to arise in any Web services composition, like downtime services, modifications in the business logic or even new policies to govern the composition. Also low-level specification of these new changes, which would be integrated at runtime in the BPEL process, will be far from being used conveniently. Moreover, the complexity of interaction in composite Web services and the diversity of rules and policies can lead to critical behavioral conflicts. We propose in this paper AOMD, a novel aspect-oriented and model driven approach that defines new grammar to address both adaptability and behavioral conflicts problems, and offers extension for WS-BPEL meta-model for high level specification of aspects. Further, we formally verify our proposition and we present real life case study, examples and experimental results that demonstrate the feasibility and effectiveness of our work. 
AOMD approach for context-adaptable and conflict-free Web services composition