The operation activity invokes an action against a participant. Using an operation activity is the only way that you can call a service.
The following specifications apply to the operation activity:
- An operation involves a synchronous request/response message exchange with a possible fault message.
- When an operation is invoked, it delivers a request message and waits for a response message. If a fault is communicated, the operation faults.
- How the business process communicates with a participant is left to the implementation. Use extension elements to provide implementation details.
- Use the operation element to invoke an operation on a service.
- The participant element must be used.
- The output element must precede the input element.