Chapter 3. Service Identification and Design
We have seen that services are a key aspect of any SOA, and by now we know exactly what a service is! The next step is for you to find out what services you actually need based on the requirements of clients. This process is called service identification. Once you have identified what services your clients require, you can start designing these services by designing their operations, and the input and output of these operations.
It's important to start with service identification before going into the actual details of service design. Don't start with the design until you have a business case and a real project with real consumers, otherwise you might end up investing a lot of time and money in the design and implementation of services and operations that are useless. If you are not sure whether particular operations are needed, leave them out and only design and implement the ones you need. Later on you can always expand services and add operations...