Archive for April 2007
There seems to be a very strong temptation for many people to model the flow of information in the use case model. Scott Ambler has some good advice here about what a use case is and, importantly, isn’t. In addition to some novel uses of the use case diagram – including an attempt to show structural components broken out as separate use cases (I think this was intended to aid traceability) – I’ve seen the standard misuses of functional decomposition and having one use case per user interface screen or web page. I think it is important to remember each diagram is only one perspective – only with mulitple perspectives can the whole be understood. What is of some concern is that the use case model has, in my experience, been more misused than other diagrams – does this mean that it is a difficult concept to grasp or is it not an especially useful diagram?