基于Web Service的工作流系统研究

【作者】 金星；

【导师】 董金祥； 陈刚；

【作者基本信息】 浙江大学 ， 计算机应用， 2002， 硕士

【摘要】 企业计算机应用发展经历了5个阶段：单个功能应用、部门级的集成应用、企业范围内集成应用、集成客户与供应商、跨企业集成与动态电子商务。前三个企业计算机应用阶段主要是企业内部信息集成，从供应链管理技术的应用开始，企业的计算机应用已经进入跨企业（或者称为企业间）的信息集成。跨企业的分布式工作流管理作为一种群体协同技术，在当今企业计算机应用中有着重要的地位。 本文主要针对当前工作流系统在实际应用中集成能力差、柔性差、互操作性不高、模型缺乏对分布环境的支持等等缺点，在当前飞速发展的Web Service架构之上，提出了基于Web Service的工作流系统。它具有松散耦合、低进入屏障、行业支持、高度可集成能力等等优势。本文主要讨论Web Service工作流的体系架构，工作流元模型（meta-model）和工作流执行过程中任务的动态分配等问题。 首先，对工作流管理的研究现状进行了综述，进而提出了本文的研究目标。 其次，介绍了两种具体的工作流系统的体系结构，分析了它们的缺点和优点。然后，分析了当前主流分布式技术（CORBA、DCOM、Java RMI等）各自的缺点，提出了符合当前计算机应用水平的分布式技术的特点。接着，全面介绍了当前最先进的分布式架构—Web Service。Web Service的目的是使应用程序能够在网络上进行无缝集成，而不必考虑它的编程语言和运行环境。Web Service是跨越各种平台边界的桥梁，因此基于Web Service的工作流能够跨越技术和企业的边界来对商业流程进行建模，而这恰恰是绝大多数的工作流系统的局限之处。 接着，提出了基于Web Service的工作流WSFlow系统的元模型，它由时间模型、资源模型、组织模型和过程模型五个子模型组成。其中关键的过程模型，我们使用IBM提出的基于XML的Web Service流语言（WSFL），它试图用一个有向图模型来定义和执行商业流程；它定义了一个公共接口，该接口允许商业流程把自己宣传成为Web Service。我们以WSFL为标准开发了编译制导的图形化流程建模工具。 最后，我们将Web Service工作流执行过程中对Web Service的选择（定位）问题抽象为一个数学模型，这是一个NP完全问题。我们根据这个模型提出了一个基于多启发式的任务分配算法。更多还原

【Abstract】 The development of enterprise computer applications goes through five phases: single function applications, department integrated applications, enterprise integrated applications, customer and supplying manufacturer integrated applications, inter-enterprise integration and dynamic e-business applications. The first three phases focus on the enterprise information integration, and in the last two phases enterprise computer application is rnter-enterpnse information integration. Inter-enterprise distributed workflow management is of great importance in the current enterprise computer applications. On the basic of Web Service architectures, we propose Web Service based workflow management, which is advanced in loose-couple, low cost, high integration ability, etc. The main topic of this paper is about the architecture of the Web Service based workflow, workflow meta-model and the runtime scheduling of the activities. At first, a systematic survey of Workfiow Management research is given, and then the study objectives of this thesis are presented. Secondly, we introduce two famous workflow managements?architectures and point out their excellence and shortcomings. Then we analyze the shortcomings of the main distiibuted technique (CORBA, DCOM, Java RMI) and propose the characteristics of distributed technique abreast of the times. Then we fully introduce the brand-new distributed architecture--Web Service. The purpose of Web Service is making the application integrate independent of the programming language and runtime environment. Web Service is bridge of the various platforms, so Web Service based workflow can span the edge of the techniques and enterprises to model the business process, which is just the shortcomings of most current workflow management. In the 3rd chapter, we discuss the flexible workflow model, which supports the building-time flexibility. Based on the design ideas and principles, we put forward our meta-model, which includes information model, temporal model, resource model, organization model and process model. In the key process model, we use the IBM WSFL, it takes a directed-graph model approach to defining and executing business processes; and it defines a public interface that allows business processes to advertise themselves as Web Services. Finally, we analyze the problems of dynamic Web Service locating, then puts forward a mathematical description of the scheduling of activities. It’s a NP complete problem and we put forward scheduling algorithm with multi-heuristics defined by users.更多还原