A modular event-based architecture for workflow systems

Real life work processes are dynamic and much richer in variation to be expressed by typical static workflow models. Two conflicting goals to be addressed include: flexibility to handle changing situations, and simplicity to design workflows that can be understood and implemented efficiently. This paper addresses these two issues by introducing a novel architecture for workflow systems. In this architecture, a workflow is defined in terms of modules and templates. Modularity provides simplicity and reusability for a workflow system. In our approach, problem independent modules are adopted for a special workflow system by placing them in problem dependent templates. Also different users in the system can interact with the workflow to make appropriate changes via events. Modules and templates have their own event handlers that allow them to be modified based on changes in user requests or situations. We illustrate these features in our architecture using two case studies, one in healthcare domain and another in a banking system.