关键词: 工作流, Petri网, 时间约束, 违规操作

Abstract: Time element as an important part of the work flow management, is a key factor affecting the implementation business process. Since tasks have the characteristic of a time limit in workflow, this paper analyzes time element of tasks, abstract formal description of tasks, quantify maximum time constraint of two consecutive tasks in execution process, proposes controllable time constraint Petri net（Time Constraint-Net, TC-Net） model. In order to improve description precision task time in the model, time information is added to tasks, from start execution time to end execution time, and maximum time constraint. It uses TC-Net model to represent tasks in workflow. Based on the order of between tasks, synchronization, and parallel transfer model relationship, it can refine actual business process analysis granularity. It applies one instance on TC-Net model for analysis model. The results show that the method is highly sensitive on irregularities caused by violation time, solves a single task irregularities and process cycle unreasonable problems, achieves the management and monitoring of business processes.

Key words: workflow, Petri net, time constraint, illegal operation