Specification and Verification of Workflow Applications using a Combination of UML Activity Diagrams and Event B

This paper presents a transformation of UML activity diagrams (AD) into Event B for the specification and the verification of workflow applications. With this transformation, UML models could be verified by verifying derived event B models, automatically, using the B powerful support tools like B4free. The workflows is initially expressed graphically with UML AD and translated into Event B. The resulting model is then enriched with Invariants/Assertions describing functional properties of workflow models such as deadlock-inexistence. We present translation rules of UML AD into EventB, and we propose also a translation process of UML AD into EventB specifications based on the refinement technique of Event B to encode the hierarchical decomposition in UML AD. Also, we propose a solution to specify time in Event B, and by an example of workflow application, we illustrate the proposed technique.