摘要
针对工作流系统的特点对时延Petri网模型进行扩展,提出了一种新的工作流建模方法,即扩展时延Petri网。给出了扩展时延Petri网的定义,并用该方法分析了工作流四种基本模型;给出了利用排队论和随机Petri网理论计算工作流模型时间性能指标的新方法,用这种方法可求得与实例到达率相关的工作流模型平均完成时间。最后应用上述方法讨论了工作流资源分布的几种模式,并与模拟结果加以对比,计算结果的最大误差在3%左右,说明基于扩展时延Petri网的方法是分析工作流系统时间性能的有效方法。
According to the characteristics of workflow system, extended the Petri net model. This paper provided a new method of workflow modeling, i.e. extended ETdPN,presented formal definition of extended timed Petri net. Thereafter, this new method of time expression could be used to analyze four basic workflow models, i.e. the sequence, parallel, choice and iteration model. This paper provided a new calculation method of workflow response time by using queuing theory and stochas- tic Petri nets theory. The proposed method could be particularly applied to analyze the effects of instance arrival rate on work- flow system performance. Finally, evaluated several patterns of workflow resource distribution with the proposed method. Veri- fied the validity of the proposed method by comparison between the simulated results and the calculation results. The largest relative error is about 3%.
出处
《计算机应用研究》
CSCD
北大核心
2009年第7期2593-2597,共5页
Application Research of Computers
