This article proposes a formal specification method for Web services composition based on context-aware semantic planning graph technique. The authors first use a graph planning technique to conceive an adaptable semantic Web services composition. They use an ontology based context model for extending Web services descriptions with information about the most suitable context for its use. Then, the composition problem is transformed into a semantic context aware graph planning problem to build a set of best-composed Web services based on the user's context. Because of the error-prone nature of the Web services composition process, and with the integration of context information in this process, the complexity of Web services-based systems is increasing, hence the need for formal specification and verification approaches of such systems. The authors seek to use CCA calculus, to formalize Web services composition expressed in terms of adaptable OWL-S, and transform the description of workflow patterns into the description patterns in terms of CCA, a calculus for context-aware ambients.
A comparative illustration of AI planning-based web services composition