Adapting Rigidly Specified Workflow in the Absence of Detailed Ontology

Abstract

Adaptive workflow approaches (for example, [1]) promise to provide flexibility of web service composition. However, definition-time adaptive workflow approaches (for example, exception handlers, and alternative flow selection) do not account for service environment dynamics, such as availability of new services and changing QoS parameters of services. This paper introduces a new method of automatic, run-time adaption, called workflow convergence. It utilises ontology in early development; ontology that reflects service message structures though is not semantically rich enough to support pure semantics based discovery and composition [2,3]. Industry is yet to widely embark on developing the complex semantic models that are fundamental for these approaches. Our workflow adaptation approach ensures that ontology is useful and value-added at all stages of development, thus providing an added incentive for industry to adopt such ontology modelling efforts. The convergence approach is introduced in the following section. Convergence relies on a service description approach, introduced in the last section, that utilises ontology in early development.