This is one of the possible Use Cases.
1. Abstract
Use of transformation rules to enable disparate services within an SOA to interoperate.
2. Status
Originally proposed by: DaveReynolds (based on http://lists.w3.org/Archives/Public/public-rif-wg/2005Dec/0015.html)
- Abstracted from different application integration efforts within HP. These are currently in Design Prototype stage but at least one is expected to be part of a shipping product in early '06.
3. Links to Related Use Cases
Enterprise Information Integration: There is a general class of information integration problems which involve transformation of data from several sources to some common ontology. The message transformation use case is a special case of that in which a natural (and typically small) bounded unit of data to be processed (viz. the message) which makes closed-world negation over existential data a meaningful operation.
Information Integration with Rules and Taxonomies: see above.
- There are problem several other information integration examples in the list.
4. Relationship to OWL/RDF Compatibility
The use case takes data expressed in RDF and transforms it from one ontology to another. The rules are thus required to process RDF data. The ontologies are expressed in OWL and in current work the rules need access to at least the RDFS closure of data.
5. Examples of Rule Platforms Supporting this Use Case
- Jena rules. The current implementations, of which this use case is an indirect abstraction, make use of Jena's forward production engine for RDF transformation.
6. Benefits of Interchange
- Neutral format - enabling the separate organizations at each end of the service link to publish and inspect the transformation definition, independent of the rule implementation technology.
- Future proofing - enables the implementor of the transformation mediary to switch to alternative rule implementation technologies without without requiring re-authoring of the rules.
- Reuse - enables third parties to reuse published rules to define new transformations.
7. Requirements on the RIF
- Representation of RDF transformation rules
- Support for object introduction ("gensym" of URI's, bNodes in conclusions)
- Quantification over RDF predicates
- Negation over extensional data
8. Breakdown
8.1. Actors and their Goals
- Supplier service - a monitoring service which exports a state description (I1) expressed in ontology O1 (services is run by organization A)
- Consumer service - a control or management service wishing to import a (set of) state descriptions (I2) from supplier services but according to ontology O2 (run by organization B).
- Mediary service - a service which enables hetrogenous supplier/consumer services to interoperate by transforming messages between different ontologies. In implementation terms the mediary may not be a distinct third actor but may be implemented as a feature of either the supplier or the consumer service).
8.2. Main Sequence
- Organizations A and B agree on the semantic mapping between their ontologies O1 and O2 and publishes a transformation rule set to the mediary.
- An instance of the consumer service finds it needs to obtain a data set from a supplier service which operates by a different ontology.
- The consumer service contacts the mediary to establish a mediated-communication channel in which message contents will be transformed according to the agreed rule sets defined in step 1
- Consumer requests data set from supplier via mediary, supplier's response is transformed by the mediary into the consumer's ontology using the agreed rule set.
8.3. Alternate Sequences
[Lots of variants are possible (e.g. explicit consultation of external data sources as part of the transformation). However expanding them doesn't seem important at this point.]
9. Narratives
9.1. System management
TBD
The case is a very abstracted version of several different RDF/OWL applications that arise in system management software. A concrete narrative and example data set and rules could be provided if it becomes clear this is a useful enough case to expand in such detail.
10. Commentary
It is not clear to what extent this is a RIF use case as opposed to a rule use case, but it is no different in that respect from several of the currently proposed use cases.