Towards A Unified Model for Workflow Processes

In workflow management, one of the key challenges is to provide a formal semantics to workflow specification and to unify workflow coordination at both orchestration and choreography levels. This paper describes the formalisation of workflow processes using the process algebra CSP. We presents the formalisaton of van der Aalst et al.'s twenty control flow workflow patterns. A business process scenario, focusing on orchestration and choreography, is examined. The result of the case study is a CSP model which gives precise semantics to both static and dynamic control flows of the business processes orchestrations and choreographies. CSP's behavioural models and their respective refinement relations make it suitable for modelling complex services orchestration and choreography. Moreover, coupled with CSP is an industrial strength automated model checker FDR, which gives CSP an advantage over other process algebras in automatic verification