Using a Pub/Sub Engine as Event Server in a Workflow Management System
Original Publication Date: 2001-Oct-12
Included in the Prior Art Database: 2003-Jun-20
1. Introduction Workflow management systems  support the definition and execution of business processes. The major constructs in drawing processes are activities and control connectors. The activities describe the tasks to be performed, and the control connectors describe the potential sequence in which the activities are to be carried out. Figure 1 (all figures copyrighted IBM/Prentice Hall). shows schematically the structure of such a process graph. Please note that this is for illustration only; workflow management system may use more primitive metamodels for describing business processes (to the extent that they use a simple block structure with implicit control connectors). Figure 1 Process Model Activities are represented as named circles; the name typically describes the purpose of the activity. Activities come in various flavors to address the different tasks that may need to be performed. They may have different activity implementations to meet these diverse needs. Program activities are performed by an assigned program, process activities are performed by another process, and event activities implement the capability to wait for some external action to happen.