Web services reduce programming complexity because application designers do not have to worry about implementing the services they invoke. Interactions in Web services are bound dynamically at runtime. A service requester describes the features of the required service and uses the service broker to find an appropriate service.
A Web services component has this life cycle:
Creation
The Web services provider creates the service component by defining its interfaces and invocation methods. WebSphere Application Server - Express supports Java beans, DB2 Universal Database stored procedures, and Bean Scripting Framework (BSF) scripts.
Publication
The Web services provider publishes the service component to a repository. The Web services broker categorizes the new Web service within its listing.
Location
The Web services requester looks up, or locates, a Web service component through the service broker.
Invocation
Once the service requester locates the service component, it invokes and implements it.
Unpublication
When the Web service provider decides that a Web service should no longer be available, it removes, or unpublishes, the Web service from the repository. The service broker likewise removes the service component from its listing.