Workflow management is concerned with automated support for business processes. Workflow management systems are driven by process models specifying the tasks that need to be executed, the order in which they can be executed, which resources are authorised to perform which tasks, and data that is required for, and produced by, these tasks. As workflow instances may run over a sustained period of time, it is important that workflow specifications be checked before they are deployed. Workflow verification is usually concerned with control-flow dependencies only; however, transition conditions based on data may further restrict possible choices between tasks. In this paper we extend workflow nets where transitions have concrete conditions associated with them, called WTC-nets. We then demonstrate that we can determine which execution paths of a WTC-net that are possible according to the control-flow dependencies, are actually possible when considering the conditions based on data. Thus, we are able to more accurately determine at design time whether a workflow net with transition conditions is sound.

关键词： Workflow nets,  Transition condition,  Verification,  Process model