I've recently finished reading "writing effective use cases" by Alistair Cockburn.
I'm looking at building a web application that sits upon 2 web services. Should I have use cases for "web application requests data from service" that corresponds to "user wants data from web application".
I see 3 options.
- Treat the underlying systems as actors and mention them in a whitebox fashion. E.g. user submits to webapp and webapp transmits to web service.
- Treat them as blackbox and write the submission use case for the user and a transmission use case for the webapp
- Treat it as too low of a use case, too much implementation details and just treat the webapp as a black box for use cases. Service behavior descriptions belong elsewhere.
Maybe other options. Does anyone have experience? Or a better understanding of how use cases should be written when dealing with multiple applications that are considered part of a single system.