一种支持简便重构的过程元模型

A process meta-model to support portable reconfiguration

工作流提倡过程逻辑与业务逻辑分离的理念,然而,业务过程中普遍存在的过程-业务动态关联的特性使这一理念在实际中难以得到贯彻,过程控制与业务处理常常以程序代码的形式耦合在一起,导致业务过程建模复杂,过程重构工作量大且不易实施。分析了WFMC元模型在过程逻辑表示方法上的局限性和难以支持业务过程简便重构的原因,提出了一种新的过程元模型—ESR元模型,在模型中加入了事件、状态和规则等模型元素,能够以规范的形式通过过程定义的方法表示过程-业务的动态关联;基于ESR元模型的工作流模型框架清晰划分了过程逻辑与业务逻辑的界限,对"刚性过程"和"柔性过程"使用统一的过程定义方法进行建模,更好地支持了过程逻辑与业务逻辑的分离;当过程逻辑发生变化时,根据不同的变化内容,可以在不同的模型层次上对过程定义进行修改以应对系统变更的需求,从而实现过程的简便重构。

The idea of separating process logic from business logic is promoted by workflow. However,it＇s hard to be carried out in reality because of the ubiquitous dynamic relevance between process and business in the business process. Process control is usually coupled with business process in the form of program code,which makes process modeling complicated and brings a heavy burden to process reconfiguration. We analyze the Workflow Management Coalition （WFMC） process meta-model,which indicates that the limitations of the model in the expression of process logic cause the difficulty of supporting convenient reconfiguration of business process. So a new process meta-modelcalled Event-State-Rule （ESR） meta-model, is presented. Some elements are added to the proposed model, such as events, states and the rules with which the dynamic relevance between the process and the business can be normally expressed by means of process definition. The boundary between process logic and business logic becomes explicit under the framework of our model,which helps to separate process logic from business logic far better. Besides, rigid process and flexible process can be both modeled by using unified process definition. When process logic varies, process definition can be modified on different model layers according to variation requirements, thereby,portable reconfiguration of the process is implemented.