Research On Dynamic Workflow Technologies On The Basis Of Reflection And Web Services

With the change of requirements and the advance of technologies, especially the popularization of computer networking, enterprises put forward more demand toward their information systems. They require that enterprise information systems not only manage resources and processes within their organizations, but also sustain the collaboration between enterprises. The enterprise information systems need to integrate all kinds of applications quickly and flexibly, and make them collaborate to provide integrated services to the core businesses. Process-oriented and more flexible information system's infrastructure has become a focutal point in this connection.Characterized by striding over business domain and software domain, workflow technology can play an important role in establishing the infrastructure. Workflow has been a hot topic in IT field for quite a while and many workflow systems have been developed. However, current workflow technology still provides insufficient support for coping with unpredictable changes. Supported by the project of National Natural Science Foundation of China"Research on Technologies for information Systems Evolution Based on Reflective Workflow and Dynamic Architecture", this dissertation studies some key issues in dynamic workflow and discusses our efforts in solving some of the problems. The main research work and achievements include:Reflection is a technique that can enhance system's flexibility and has been adopted in programming language, middleware, operation system, etc. We proposed a reflective model called RWM for managing dynamic workflow. In our approach, four metaobject constitute a meta space. In RWM, a workflow is reified by these metaobject to reflect its topology, function, behaviour and states. The workflow can be adjusted through the interface of a metaobject, which is called Metaobeject Protocol. The Metaobejct reflects workflow orthoginally, makes adjustments easier.This dissertation proposed a workflow system named WARW based on Web Service and RWM. WARW makes it possible to integrate inter-enterprise applications. In order to select Web Services dynamically at run time, a method to provide Quality of Service for Web Services is also provided. It uses tModel in UDDI to extend the description information of Web Services.A prototype system of WARW is designed and implemented. The WARW is implemented based on J2EE and Web Services. It consists of a process monitoring module, a client management module, an enterprise resources management module, a task management...