A framework towards Web services composition modelling and execution

This paper describes a framework that provides abstraction at the execution level of business process modelling. It aids business users in designing and enacting web services-based business processes (or in other words, web service compositions) in Business Process Execution Language for Web Services (BPEL4WS). We elaborate on the information for modelling the composition required from the user, with abstraction from the syntactic details of BPEL4WS being the major concern. An intermediary relational model has been devised to store the information, which is complete in all aspects, for direct mapping to the execution language. The notion of control-rules has been introduced, with the help of which the behavioural aspects of the composition are captured. We also present algorithms that extract data and automatically infer further information from the relational model. The BPEL4WS code thus generated is portable and can be enacted in any BPEL4WS complaint orchestration engine