Ontological Implications of Service- Oriented Architecture Michael Gruninger NIST / Institute for Systems Research University of Maryland

Tasks Service discovery Find web services that achieve F, and where if B occurs then it occurs before A. e.g., my credit card is charged only after the book leaves the warehouse Service composition

Semantic Web Service Ontologies Specify the semantics of the process model underlying services, together with a notion of messages and dataflow. Axiomatize this semantics within some logical language (OWL, Common Logic) Existing ontologies OWL-S SWSF (Semantc Web Services Framework) WSMO (Web Service Modelling Ontology)

SWSF FLOWS-core –Service, AtomicProcess, composedOf, message, channel Control Constraints –Split, Sequence, Unordered, Choice, IfThenElse, Iterate, RepeatUntil Ordering Constraints –OrderedActivity Occurrence Constraints –OccActivity State Constraints –TriggeredActivity Exception Constraints –Exception

Ontologies for Semantic Web Services The software applications within services will typically be using different ontologies, and any service-oriented architecture must support the semantic integration of these ontologies Required Capabilities Advertise/publish application ontologies Automatically generate semantic mappings between ontologies used by different services. Twenty Questions Semantic Mapping Tool and Process Information Exchange protocols