A FORMAL FRAMEWORK TO SUPPORT WORKFLOW ADAPTATION

A workflow system automates a business process, enabling documents, information and tasks to be passed among participants following a set of defined rules. The system needs to address changes that are frequently encountered in a complex heterogeneous environment. In such scenarios, a formal description of an adaptive workflow system will lead to greater reliability and clearer understanding of the entire system. Previous studies on workflow formalization have focused on specific perspectives, for example, deadlock and reachability in a workflow process. However, there is a close relationship between workflow components. Therefore a unifying description is an aid to understanding workflow behaviour. In this paper, the main workflow components are described in a unifying framework WfSL (Workflow Specification Language) through a combination of process algebra and Z specification. The former is used to describe workflow processes and the latter to specify the workflow information model and workflow organization model. An integration semantics is presented for data state transition and process state transition. The framework can be used for verifying workflow correctness when changes are made to the workflow.