一种基于策略的工作流过程元模型

随着工作流的广泛应用，人们对工作流系统的灵活性提出了新的要求。作为工作流系统的核心，工作流的过程元模型很大程度上决定了工作流系统的能力。结合互联网工程任务组（Internet Engineering Task Force，IETF）提出的策略的概念和策略部署模型，提出一种基于策略的工作流管理系统，并结合工作流系统的特点，提出了描述工作流策略语言，使用基于策略扩展的Petri网建立工作流过程模型的方法。基于该元模型的定义的工作流具有较好的灵活性，并对工作流的运行期实例的动态修改提供支持。

A Policy -based Workflow Process Meta Mode

As the wide use of workflows,flexibility is new requirement of them.The ability of a workflow system depends greatly on the process meta model which is the heart of a workflow system.Referencing the concept of policy proposed by Internet Engineering Task Force,this paper proposes first a new process meta model based on policy,and then proposes a workflow policy language to describe the workflow process model,finally illustrates how to model the workflow process model using policy-enhanced Petri net.This process meta model is flexible and provides support for dynamic modifying to the workflow runtime instances.