New hierarchical workflow process model based on Petri nets

To satisfy the enterprise process modeling requirements on the capability of powerful expression and analysis, a new hierarchical workflow process model based on Petri nets was proposed. Based on a rigorous analysis of various workflow models, a hierarchical workflow process model was provided through expanding the basic Petri net. It was composed of description model DWF_net and analysis model AWF_net. DWF_net was designed for directly describe various complex processes, such as multiple instances, cancel activity, and advanced parallel and synchronization. Based on Petri nets, control variable was added to DWF_net and transition was classified as transition entry and transition body. Transition could read or write control variables. Transition entry function could eliminate the conflicts of DWF_net by judging control variables. Transition body function could read/write control variables. As the analysis model of DWF_net, AWF_net peeled the semantic information of specific case from DWF_net. And all achievements of analysis techniques of Petri nets could be directly used to analyze models. Finally, some application examples were introduced to illustrate how to apply the proposed model to describe and analyze various complex processes.