基于Pi演算的跨组织工作流建模研究

Research on Cross-Organizational Workflow Modeling Based on Pi-Calculus

传统的工作流建模方法主要用于描述组织内部流程,因而难以描述跨组织工作流面向流程、组合、抽象、涉及多个自治系统通信合作的新特点.针对此问题,提出了一种基于Pi演算的跨组织工作流建模方法,利用Pi演算的并发计算操作符,将跨组织业务流程建模为一组自治且并发执行的组织内子流程的组合,子流程建模为组织内本地流程定义和组织间控制约束的组合.基于Pi演算的弱互相似理论,验证了两个跨组织子流程外部行为的相等性,用于帮助组织内私有流程的外部抽象.基于该方法建立的跨组织工作流模型在子流程间建立了一种松耦合的关系,适用于动态的跨组织环境,同时基于严格的形式化方法,便于分析和验证.

Cross-organizational workflow has some different characteristics compared with normal workflow, such as process-oriented, compositionality, abstraction, involving communication, and collaboration of several systems. Traditional workflow modeling methods cannot meet these new requirements because they don＇ t have mechanisms to support abstraction, and there are no standards and concurrency operations to obtain bigger models by combining small ones in these modeling methods. Aimed at this problem, a cross-organizational workflow modeling method based on Pi-calculus is presented and the consistency and compositionality of the model are analyzed. Using concurrent operators Pi-calculus provided, a cross-organizational business process is modeled as a composition of a set of autonomy and concurrent intra-organizational sub-processes, and an intra-organizational sub-process is modeled as a composition of a local business process definition and control constraints between organizations as well. Based on weak bisimulation theory of Pi-calculus, external behavior equivalence of two cross-organizational sub-processes is defined, which can help building abstract of an internal private business process. Compared with the traditional methods, this new cross-organizational workflow modeling method builds a loosely coupled relationship among sub-processes, which makes this model adapt to dynamic cross-organizational environment. And this model is based on strict formal method, which facilitates the analysis and verification of business process models.