Statistics: (734 Views) (0 Comments) Posted by: SuperUser Account on Tuesday, May 01, 2007 Categories: Activity Diagram, Unified Modeling Language (UML)

The core purpose of software development is to provide solutions to customers' real problems. Use cases are a vital aspect of a technique that has been used successfully to ensure that development projects actually focus on these problems. They are used to discover, capture, and present customer requirements in a form that is accessible to developers, testers, and other stakeholders in a development project. To detail a use case, it is critical to capture basic, alternate, and exceptional flows of execution, which represent major and minor threads of execution the system encounters as it processes customer requests.

Using the "standard" use-case form, these flows can be captured using plain English to describe sequential activities. These descriptions are quite detailed, however, and they can be difficult to decipher -- especially within a complex set of use-case scenarios.

This article describes another way to capture these flows: by using Unified Modeling Language (UML) Activity Diagrams that depict the flows as "roadmaps" of system functional behavior. These roadmaps are analogous to AAA (Automobile Association of America) roadmaps, in that they show what routes you can take but do not indicate whether you will take them.

An AAA map, moreover, supplies only enough information to identify locations of interest, leaving detailed descriptions of the road for companion travel guides. Similarly, Activity Diagrams show a comprehensive summary of use-case flows but leave the design details up to other artifacts.

We will also take a brief look at other ways to use Activity Diagrams during the development lifecycle.

Author: Ben Lieberman