Petri Net-based Workflow Technology Research And Applications

The workflow management technique separates the process logic from the applications, achieves the purpose of process modelling, recompose and reuse. Current workflow modelling methods provide little support for the flexible and adaptive modelling, so become hard to adapt to the dynamic change with the business environment. On the other hand, there have little research on the specification and verification of workflow model and still doesn' t have any mature analysis and verification method. This paper takes the workflow modelling method based on Petri nets as foundation, has carried out research and development work as following:Based on the analysis of participant mechanism in workflow, a Petri net-based workflow participant modelling method is put forward. The static, competitive, priority-ranked and commitment models of participant and their Petri net representations are given. With Petri Net-based workflow place/transition refinement, this paper indicates the relationship between task assignment and participant' s state in workflow execution, showing that the real executive path of workflow process instance is dynamically determined by the participant' s state.The classic P/T nets don' t have enough description abilities to represent the uncertain events and uncertain times in the workflow process, this paper integrates the fuzzy theory with the Time Petri Net, presents a modelling method named Fuzzy Workflow Net (FWFN). This method has some degree of flexibility, can adapt to the change of environment.The temporal logic is used to specify the requirements and properties of the workflow model. This method has more descriptive power and is flexible, easy to be used. Based on the tableau and on-the-fly methods of temporal logic, this paper presents a realization method that mainly uses the Bllchi automata to validate the workflow model. It improves the rationality and reliability of the workflow model.On the foundations of theoretical research, we have developed a workflow management system. This system is developed under the background of the "Government Office Automation System of Flood-Control Office in Heilongjiang Province" and based on the B/S three layers structure. In some distance, this system has performed the productions of the theoretical research.