Enterprise applications must meet the needs and requirements of their user population. Use Cases are a proven and effective technique for organizing and documenting the functional requirements of an automated system.

Functional requirements are the cornerstone of any enterprise application. An application exists to enable and support a business process. Use Cases are a technique that can be used to organize and document the functional requirements of anything considered a ‘system.’ The most prevalent application of Use Cases and the focus of this note is Use Cases applied to automated systems.

What Is a Use Case?

A Use Case tells a story about how a system will be used to achieve a goal from the perspective of a user of that system. The people or other systems that interact with the Use Case are called “actors.” Use Cases describe what a system must be able to do, not how it will do it.

A Use Case Model consists of a diagram (see Figure 1) of the Use Cases and a text document for each identified Use Case. The Use Case documents are embedded in, or attached to, a Requirements document to provide the full view of the functional requirements.

Use Cases are translated into functional specifications and, eventually, test scenarios. When complete, the system should fulfill a Use Case whenever a user engages the system.