The Whodunit system design had great start, and giving more detail is next suitable step in design process. Collaboration diagrams help give this extra detail.
Create a collaboration design and description in Microsoft Word which addresses following requirements:
Create UML collaboration diagrams by using Microsoft Visio or another drawing tool capable of preparing properly formatted UML collaboration diagrams. Your diagrams must serve to document selected portions of overall design you feel could benefit from additional detail given by this kind of diagram, but there must be minimum of three diagrams included in this phase.
Create diagrams into collaboration design and description document in Microsoft Word and add thorough description of your diagrams.
Make suppositions as essential, but make sure to state your suppositions.