Research And Implementation Of Lightweight Workflow Engine

Workflow engine is the core of background in Workflow Management System(WfMS), which is responsible for interpreting the model of workflow definition, controlling and maintaining the running of process instance. It is the key of a WFMS. At present, there are some shortages in WfMS, such as absence of flexibility, much complication, and so on. By making a in-depth study of current mainstream workflow products and analyzing XPDL(XML Process Definition Language) presented by WfMC(Workflow Management Coalition), from the point of view of lightweight and flexibility, this paper designs and implements a new workflow engine based on Relational Database and XML. The engine, which is layered and based on the theory of IoC( Inversion of Control), takes full advantage of the technology of relational database.The main contents in this paper are as follows:1. Give the architecture and primary design of engine, judging by lightweight, XML and Relational Database-based design philosophy, and illuminate its implementation mechanism and running theory.2. Build the model of the engine process definition, based on FSA(Finite State Automaton),which is the theory basis of engine , and give the implementation.3. Give the organization structure and role model of engine and the implementation.4. Give the detailed design and implementation of executing engine.5. Describe the strategy based on task and process instance.6. Analyze the exception that may exist in the running process of engine, and explain the mechanism of capturing exception.7. Give the detailed implementation of a workflow instance combining with an actual application and an actual business process.The actual application indicates that, this engine can deal with common workflow pattern, improve the efficiency of the second development of information management system based on process, shorten the time for developing process information system, and reduce the cost of development.