Rule-Based Semi Automatic Web Services Composition

In this paper we propose a rule-based approach for the semi-automatic Web services composition problem, giving end-user the control to guide the overall composition process. The end-user builds the composition flow by selecting known Web service instances or constrained Web service types, called nodes, and by connecting them using a set of control/data flow connectors. The specified nodes will then be bound to concrete Web service instances using a set of rule-based queries satisfying the associated constraints. When compared to the traditional approaches, our model is declarative, allows for specifying both the functional and non-functional requirements, provides connectors that include both the data and control flow aspects and aims to choose the one best matched Web service for a node instantiation.