摘要
近几年来,工作流管理技术被业界广泛采用并得到了迅速发展。工作流管理最重要的功能之一就是工作流建模。这些预定义的过程模型必须能很好的反映实际业务流程,因此需要找寻灵活的工作流过程形式化表示方法及过程的执行策略。
Aalst的工作流网已被众多研究人员所认同,它是基于经典Petri网所建立的。但是,传统Petri网具有一些固有的缺陷:当系统过于复杂时,由于状态太多,容易引起状态空间爆炸问题。因此,本文对经典Petri网进行颜色扩展,提出了基于着色Petri网的工作流网模型,解决了建模过程中的两大问题:资源调用问题及业务处理过程的建模问题。该模型对业务过程的描述有很强的表达能力,支持对工作流模型的分析与验证。本文对该模型进行了包括过程模型和资源模型的详细设计。根据Client/Sever思想,将资源从流程中独立出来,采用统一的资源管理器管理。设计了资源管理器的基本模型,解决了不确定性活动的建模问题和资源的申请/释放问题,以及多个实例时的可能发生的混乱状况。在Aalst的任务结构映射算法的基础上,结合着色Petri网的性质,提出了一种工作流程模型到着色工作流网的映射算法,采用对链表遍历的方式来映射业务流程。该算法先给出基本结构的映射规则,然后遍历工作流程模型即有向图,对图中的每一个状态结点应用相应的映射规则进行着色Petri网映射,再把转化后的着色Petri网模型映射到着色工作流网,此映射算法能实现着色Petri网建模。
在给出建模方法的同时,本文还论述工作流模型的合理性验证。介绍了仿真分析方法,并以一系列的实例说明了每种分析方法的具体应用。论文最后给出了一个实际的应用案例的过程模型。
最后对本文的研究工作进行了总结,针对不足之处提出了改进的措施,并展望要进一步深入研究的方向,为后续工作奠定了基础。
Recently, Workflow Management technology, a rapidly developing technology, has been applied to many trades. The most important function of workflow management system is modeling. The model must reflect business process, and it’s necessary to find a way to express workflow process.
More numerous scholars and specialists have identified with workflow net based on classical Petri net. It, therefore, can describe sequence, concurrent and conflict. And it makes system visual and understandable. There, however, are some limitations:It is difficult to control flow of business, and has too much state when system is very complicated. So the paper extends classical Petri net by color. Then it Puts forward workflow net based on Colored Petri net. This model consists of Process model describing business process and resource model describing enterprise resource. It has a strong ability to express the business process, supporting the analysis and validation of workflow model... This thesis puts forward a detailed model design, including the process model design and the resource model design.
A resource manager is modeled; the resource manager assigns and releases resource. Tasks and sub-procedures inside a procedure, communicate with the resource manager and the resources via the other connectors. A way of mapping arithmetic from business process to workflow net is designed in this thesis based on task structures which is first created by Aalst. The thesis designs the algorithmic and its realization.
The thesis debates two workflow model analyzing technologies: qualitative:Analysis and quantitative analysis. In addition, it describes simulation analysis method and concrete application by a series of examples. In the end, the thesis represents an application case and models its business Process.
Finally, the thesis summarizes the research work, points out the disadvantages of this paper and gives some ideas for the further work.
引文
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