真并发等价性下的流程模型转换方法

针对工作流建模过程中流程模型的演化问题,在真并发等价性概念下,提出将图形化控制流模型转换为顺序与并发结构可分隔处理的可分离形式的方法.采用自由选择工作流网建模控制流模型,以完全并发互模拟为真并发等价概念,定义两个安全网间是完全并发互模拟关系的充分条件；基于Petri网的网展开,提出获得工作流网的可分离形式的局部网展开算法；通过证明局部展开网与原工作流网满足完全并发互模拟的充分条件,保证两个网模型的等价性.所提转换方法与已有方法相比,能够保留并发层次,且所需步骤更少,有利于流程模型的演化.

Transformation of Process Models under True Concurrency Equivalence

A method to transform graphic control flow models into separable forms is proposed under the true concurrency equivalence notion to evolve process models during the workflow modeling.The separable form means that sequential and concurrent structures can be handled separately.Free choice WF-nets are used as control flow models,and fully concurrent bis-imulation is chosen as the true concurrency equivalent notion.Then the sufficient conditions that two safe nets are fully concurrent bisimilar are given.A partial unfolding algorithm is proposed for WF-nets to obtain their separable forms based on the net unfolding of Petri nets.The equivalence of a partial unfolding net and its original WF-net is ensured by proving that both the models satisfy the sufficient conditions of fully concurrent bisimilation.Comparisons with existing methods show that the proposed transformation method could preserve the concurrency level with less steps,and hence facilitates the evolvement of process models.