The Rule Engine as an executable class, callable using proprietary API or the JSR94 API. Rule Engine can be an embedded component or deployed within a pool as reusable components.

When designing a SOA and the different decision services, the architect should focus and apply the same design pattern as other business services. The rule engine technology choice is an implementation decision not a service design one. The service design has to address:

• the service definition: one or more operations linked to the same data semantic
• the operation call approach: synchronous/ asynchronous, stateless/stateful, header based or carrying payload, use of faults or not
• the exception reporting

The service implementation using a rule engine has to look at:

• the transaction propagation
• the reference data caching
• the parsing of input message: the claim data
• the loading of the related data: the policy related to the claim, or the insured person profile
• the preparation of the output message: the result and may be some other technical data