When deep diving into details of defining software or systems requirements we often use use case diagrams in order to illustrate the different usage models of the designed system, while noting users, components APIs and interactions.
EventStudio System Designer allows you to create use cases diagrams, collaboration diagrams and derived interface details while using a proprietary modeling language.
After short to medium learning period you will be able to create use case diagrams in a very simple manner, but more importantly very easy to maintain and reuse. After couple weeks of usage I’m far from knowing all options of the tool, but am able to enjoy the easy way of creating diagrams (unlike Visio or Visual Studio).
The diagrams can be viewed in PDF file or embedded to word document, and you will also get HTML summary reports which analyze what interfaces each component requires.
Worth trying. Get your free trial here: http://www.EventHelix.com/EventStudio/