Composition of executable business process models by combining business rules and process flows

Emergency of Web services has promoted a new paradigm of a business process which is called the Service-Oriented Business Process (SOBP). The SOBP uses Web services as an implementation platform for activities that belong to a business process, and is modeled with a Business Process Definition Language (BPDL). A de facto standard of BPDLs is the Business Process Execution Language for Web Services (BPEL4WS), but the BPEL4WS requires extra mechanisms to explicitly specify process states in a process model and to separate business rules from process flows. By specifying the states explicitly and separating the business rules, a SOBP gets abilities to rapidly monitor a process in execution time, to efficiently define state-dependent process behavior, to freely change the business rules without modification of the flow, and to firmly guarantee business security by hiding the rules. In order to explicitly specify the process states and to separate the business rules from the process flow, an approach to a state-driven specification of a business process is suggested in this paper. The suggested state-driven approach inserts process states into a process model using process units, and separates the business rules from the process flow by regarding the states as the milestones which indicate where the rules are separated. Because the suggested approach supports a composition of a BPEL4WS executable process by combining the business rules and the process flow, the suggested approach can be used as a complementary design method of a BPEL4WS process model, and not as a substitute method of the BPEL4WS model.