Design and Implementation of the YAWL System

This paper describes the implementation of a system supporting YAWL (Yet Another Workflow Language). YAWL is based on a rigorous analysis of existing workflow management systems and related standards using a comprehensive set of workflow patterns. This analysis shows that contemporary workflow systems, relevant standards (e.g. XPDL, BPML, BPEL4WS), and theoretical models such as Petri nets have problems supporting essential patterns. This inspired the development of YAWL by taking Petri nets as a starting point and introducing mechanisms that provide direct support for the workflow patterns identified. As a proof of concept we have developed a workflow management system supporting YAWL. In this paper, we present the architecture and functionality of the system and zoom into the control-flow, data, and operational perspectives.