Notice of RetractionFormalizing workflow patterns with Extended Petri-Net

Notice of Retraction

After careful and considered review of the content of this paper by a duly constituted expert committee, this paper has been found to be in violation of IEEE´s Publication Principles.

We hereby retract the content of this paper. Reasonable effort should be made to remove all past references to this paper.

The presenting author of this paper has the option to appeal this decision by contacting TPII@ieee.org.

The essence of workflow systems is workflow patterns. Languages based on Petri nets perform better when it comes to state-based workflow patterns. However, some patterns with complex semantic can not be described by Petri-net. It inspired us to develop a new Extended Petri-Net (EPNet). EPNet extends the Petri-Net through adding some new elements and the corresponding mechanisms. D element and C relation are introduced into EPNet for describing instance runtime data and complex relation of computing and communication. A task has three parts: entry function, body function and exit function. Soundness of an EPNet can be converted to the analysis of liveness and boundness of corresponding Petri-net. All workflow patterns can be directly described using EPNet. This paper investigates the issue and introduces a collection of workflow patterns formalizations, each with a sound formal definition and execution semantics. The formalizations can be used as a foundation for pattern-based workflow execution, reasoning, and simulation as well as a basis for future research on theoretical aspects of workflow.