流程仿真的多层次PERT-Petri网模型

复杂流程中的工序持续时间有着很强的随机性,并存在资源约束问题。首先分析了常见的PERT和Petri网在流程仿真中的应用特点,提出了多层次PERT Petri网模型,给出了该模型的建模过程和递归仿真算法。该模型在上下层次分别采用PERT和Petri网对流程进行描述,充分利用了PERT直观简便的特点和Petri网在随机性和资源约束上的描述能力,有效地解决了复杂流程的建模与仿真问题。最后给出了一个例子,表明该模型更容易理解和构造。

Multi-level PERT-Petri net model for process simulation

Duration of working procedure is stochastic and is influenced by resources in complex process. There are some existing models which can be used in process simulation, but these models have many deficiencies. On the basis of analysis of the application of PERT and Petri net on process simulation, this paper presents the multi-level PERT-Petri net model and gives the modeling method and recursive algorithm of this model. This model divides the process into multi-level, then uses PERT model in top level and Petri net model on bottom level. It has advantages of PERT and Petri net, and can be used in the complex process simulation and analysis. Finally, an example is given.