Despite years of evolution in systems and SOA, people are still divided by differing uses of common terms. Definitions of routinely used words like “service,” “component,” “system,” “task,” and so on, and how those terms relate to each other, can have varied meaning depending on who or what product or tool is doing the defining. In particular, business and technology people may not assign the same definitions or understanding to a concept.
The SOA Work Group said the ontology is designed to be used by business people, architects and developers.
According to Jensen, the ontology group had to decide on a scope for the standard that would be “small enough to be manageable, but a rich enough language to be useful.” He said it also needed to be consistent with existing standards. The group settled on defining “concepts so fundamental that it would be hard to have a meaningful conversation about SOA systems without them.”
Coming to terms with SOA ontology
For example, the ontology standard defines terms like element, system, human actor, task, service, service contract, service interface, composition (with pattern orchestration, choreography and collaboration), service composition, process, policy and event.
The SOA Ontology is also intended for use with other industry standards, Jensen said. The Oasis Group’s SOA Repository Artifact Model & Protocol (S-RAMP) will be utilizing the ontology standard, he said. In fact, the S-RAMP group worked with the ontology group and provided input as to what they needed. “We had a rich exchange between the S-RAMP group and the ontology team,” Jensen said.
Dr. Chris Harding, the Open Group’s SOA Work Group forum director, said the S-RAMP collaboration is a successful example of “one industry body leveraging the work of another industry body group,” which is the ideal.
Version 1.0 of the S-RAMP specification was jointly authored by HP, IBM, Software AG, and TIBCO. The first meeting of the Oasis S-RAMP Technical Committee is December 14.
Standard contributor Jensen said the ontology group made sure its definitions were consistent with the way terms were used in existing standards such as Oasis Service Composition Architecture (SCA) and the Object Management Group’s Business Process Modeling Notation (BPMN).
While he acknowledged there was “some level of tension at the detailed syntactical level” among the standards, “we were able to extract enough common semantics that we believe it’s consistent with all three. It turns out there were fewer differences than people might have thought, which is a good thing, because it means the industry has evolved to a common understanding.”
Harding said the ontology standard is the fruition of work begun several years ago when the SOA Work Group, which formed in 2005, identified it as a necessary project.
As far as acceptance of the new standard, Jensen said, “it’s up to all vendors to say that over time if [their] products will evolve to be semantically compliant.”
The SOA Ontology Technical Standard is available free of charge from the Open Group website.
Call for Ontology feedback
SearchSOA readers: What do you think? Let us know. Is ontology needed in your SOA experience?