Onto-SOA: From Ontology-enabled SOA to Service-enabled Ontologies

The significant potential of the combination of ontologies and SOA has been recognized in the field of Semantic Web Services (SWS). The OWL-S and WSMF approaches provide us with ontology-based frameworks for WSDL web services to enable automation of high-level tasks such as discovery, invocation and composition of web services. We also investigate ontologies and SOA but our initial focus is on the software architectural aspects of ontology-enabled services We set up to define a general Ontology-enabled Service- Oriented Architectural style (Onto-SOA). Onto-SOA is independent from an ontology language and a particular web service technology and, therefore, is applicable within any approach that combines ontologies and SOA. With Onto- SOA we discover that the relation between an ontology and a service is bi-directional: not only an ontology brings shared semantics to services, but also services can be integrated into an ontology (language). The latter provides an ontology with a service-enabled mechanism capable of connecting an arbitrary service to an ontology. In order to illustrate the bi-directionality and to validate Onto-SOA, we further specialize it into MoRe - an RDF/S-enabled SOA with elements of REST web services - and then apply MoRe to the unit conversion problem in the e-Science domain.