A Novel Hierarchical Method for Decomposition and Design of Workflow Models

Modeling and analysis of large and complex workflow processes includes transformation of the process logic into a formal representation. Petri net-based modeling is convenient, but it suffers from the complexity due to states explosion problems, which make the technique less practical. In this paper, we develop simple and powerful Petri net transformations rules that can reduce or expand the Petri net model of workflow. Then we show that the modified net can be obtained without changing the correct behavior of the original net. A sequence of transformation results in a hierarchy of reduced nets that allow easy verification and hierarchical decomposition of the system. Moreover, we show that our result can be used as a design tool for the correct construction of an arbitrary class of sound workflow structures. An efficient algorithm is provided to tackle this new approach comprehensively.