Abstract

Workflow has become popular and interesting by removing control flow dependence from business software systems, just as DBMS (DataBase Management Systems) has become a separate domain by removing data dependence from business software systems. YAWL (Yet Another Workflow Language) is a completely new language with its own semantics and it is specially designed for workflow specifications that provide direct support for the workflow patterns identified. When this thesis was first conceived, no implementation based on YAWL was available. This inspired the development of this thesis. In this thesis, as a starting point, an XML workflow schema employing seven workflow patterns of YAWL was designed for users to define the workflow specification. Based on this, a prototype workflow engine supporting these seven patterns of YAWL was designed and implemented to parse and interpret the workflow in the control flow specification (the execution order) of YAWL, which is described in the XML workflow document conforming to an XML workflow schema. At runtime, the engine handles the execution order of the workflow.