I am writing the documentation of a software I have to develop. I am respecting the V model:
http://sqa.fyicenter.com/FAQ/Software-Development-Models/models_1.JPG
My question is: where should I use the UML class diagram, in the functional spec or in design spec?
The relation between the classes and the detail of the properties/methods inside those has nothing to do with WHAT the system is going to do, btu with HOW the system is going to do its job. For this reason I'd put the UML class diagram in the design spec.
Moreover I usually won't put in design spec the entire class diagram, but also some part of it (if any) focused on particular topics (subtasks of the entire system). I primarly use class diagram (and sequence diagram of course) for designing the application to make my mind clearly see the solution, but not for documenting it: the class diagram could (and will) often change from my first though, mainly due to refactoring.
