Research On Web Services Based Distributed Workflow Management System

Workflow management has evolved a mature technology during the last decade and has been applied successfully in many areas. However, two trends are coming together that are extending the business process to crossing the organizational boundaries. One is a business trend towards increasing globalization, outsourcing and consolidation. The other is the rapid improvement in Information Technology, especially the Internet and the World Wide Web. The number of collaborative business processes where multiple partners are involved is increasing rapidly. The traditional workflow technologies tending to manage single business process within one organization show their limitations while be confronted with such business processes management requirements. The new features of business processes require that the WfMSs should have distributed and loosely coupled architecture and be able to deal with workflow processes which across multiple organizations in a process-oriented manner.As a distributed computing environment, SOA and Web Services can provide a communication infrastructure for implementing distributed workflow management system. The component model and architecture of the Web Services based distributed workflow management system are introduced in this thesis. Solutions to some key problems such as distributed modeling, executing, monitoring, controlling of process and applications invoking are also presented here. The Web Services based distributed WfMS implements not only the distribution of the functional components of system and the distributed enactment of workflow engines, but also a higher-level distribution of the workflow process model.The main works and achievements in this thesis include the following aspects:1. According to the new features of business process brought by macro trends in business and technology, the opinion that traditional workflow managementsystems must break through their limitations to satisfied the requirement of process management is expressed. In addition, it is stated that distributed architecture is the direction in workflow management system development. Furthermore, SOA and Web Services are proved as suitable infrastructure of fully distributed and loosely coupled WfMS.2. The expressiveness and suitability of the Petri Net based Xinpai-driven model is analyzed in depth within the framework of a collection of workflow patterns. The result shows that Xin-pai driven model has sufficient expressive power and it is suitable for a wide range of business requirement.3. The component model and architecture of the Web Services based distributed workflow management system are illustrated.4. A method for defining distributed business processes is given. Business processes can be encapsulated into Web Services by using the mechanism of Web Services' publish, finding and binding. Thus the distributed business process can be defined at a higher abstract level by composing the Web Services.5. The solutions of distributed workflow enactment and monitoring, applications invoking in Web Services environment are described.