Saturday, January 31, 2009

UML Use Case - Includes vs Extends

A couple of developers I know asked me about the includes and the extends for use cases. "includes" is used when the included use case is always executed as a part of another user case. "extends" is used when a use case is executed as a part of another only when an exceptional condition occurs.

2 comments:

venky said...

If you have a usecase called "withdraw cash" and it had "include" with "check balance" and extends with "perform overdraw" it goes like, every time u withdraw cash YOU WILL "check balance", whereas you may or may not "perform overdraw". INCLUDE = MANDATORY & EXTENDS is OPTIONAL behavior..Hope this helps.

Gurjeet Saini said...

exactly true