Workflow management systems usually interpret a workflow definition rigidly. However, there are real life situations where users should be allowed to deviate from the prescribed static workflow definition for various reasons, including lack of information and unavailability of the required resources. To flexibilize workflow execution, this paper first proposes mechanisms that allow execution to proceed in the presence of incomplete information, by adopting presuppositions, and in the presence of negative information, by suggesting execution alternatives. Then, the paper presents an architecture for a workflow system, driven by ontologies that capture semantic relationships between workflows and resources. The architecture includes a component which uses matching techniques to find alternatives for workflows and resources.
workflow; flexibilization; ontology; matching
