CODEWITHSUNDEEP
umldiagramuse-case
SMUsamaShah
SMUsamaShah

Reputation: 7900

What is the difference between 'includes', 'extends' and 'uses'?

In a use case diagram what is the difference between <<includes>>, <<extends>> and <<uses>>? Are <<includes>> and <<uses>> are the same thing?

Upvotes: 23

Views: 67911

Answers (4)

Motti
Motti

Reputation: 114835

The include relationsionship is usually used in use cases to signify that one use case uses the other. In contrast the use relationship is used in UML to show dependencies between models, that one model requires the other in order to function.

Here are the quotes from IBM's documentation.

Include relationships
In UML modeling, an include relationship is a relationship in which one use case (the base use case) includes the functionality of another use case (the inclusion use case). The include relationship supports the reuse of functionality in a use case model.

Usage relationships
In UML modeling, a usage relationship is a type of dependency relationship in which one model element (the client) requires another model element (the supplier) for full implementation or operation.

To recap (as I understand it) includes is a dependency in the model while use is a dependency in the functionality.

Upvotes: 6

Krishna
Krishna

Reputation: 1382

"includes" and "uses" indicates the mandatory use case where as "extends" indicates the optional use case.

Upvotes: 4

Guest
Guest

Reputation: 101

includes and uses are the same. From http://www.agilemodeling.com/essays/useCaseReuse.htm above

An include dependency, formerly known as a uses relationship in UML v1.2 and earlier

Upvotes: 10

DwB
DwB

Reputation: 38348

Nice writeup here: http://www.agilemodeling.com/essays/useCaseReuse.htm

Summary from that article:

  • An extending use case continues the behavior of a base use case.
  • An include dependency is a generalization relationship denoting the inclusion of the behavior described by another use case. The best way to think of an include dependency is that it is the invocation of a use case by another one.
  • The inheriting use case would completely replace one or more of the courses of action of the inherited use case.

Upvotes: 8

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