| 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. |
