CSCI 6448

Object Oriented Analysis and Design

Use Case Generalization

This page includes material from Alistair Cockburn's book: "Writing Effective Use Cases". © 2001. Addison-Wesley.

It is being used to support Lecture 9, Slide 17 of Dr. Kenneth M. Anderson's Spring 2003, CSCI 6448: Object-Oriented Analysis and Design class.

As such, the images on this page, are Addison-Wesley, © 2001.

Generic Use Case

Given the following Use Case:

You can model the relationship between use cases with either a direct "includes" relationship or with an inheritance relationship.

Pitfalls

Beware common pitfalls when using an inheritance relationship among use cases and actors. The figure below is meant to show that only a senior agent can close a big deal. But because a subclass can substitute for a superclass, it also says that a sales clerk can close a big deal as well.

The way to avoid this error is shown below.