What is extend and include in UML?

The include relationship supports the reuse of functionality in a use-case model. Extend relationships. In UML modeling, you can use an extend relationship to specify that one use case (extension) extends the behavior of another use case (base).

When to use include extend stereotypes in UML?

“Include” is used to extend the base use case and it is a must condition i.e. included use case run must run successfully to complete base use. “Exclude” on the other hand is optional use case which extends the base use case, base use case can run successfully even without invoking/calling the extending use case.

What is difference between include and extend?

In simple words, the difference between include and extend is that ‘include’ is for adding methods only to an instance of a class and ‘extend’ is for adding methods to the class but not to its instance.

What is an extend in use case diagram?

The extension use case consists of one or several behavior sequences (segments) that describe additional behavior that can incrementally augment the behavior of the base use case. Each segment can be inserted into the base use case at a different point, called an extension point.

What is meant by the << includes >> relationship in a use case?

The includes relationship (also called uses relationship) describes the situation in which a use case contains behavior that is common to more than one use case. In other words, the common use case is included in the other use cases. A dotted arrow that points to the common use case indicates the includes relationship.

What is include in UML?

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.

What is an << includes >> relationship?

<> relationships: Include relationship is used to include one use case within the behavior sequence of another use case. An include relationship between use cases means that the base case explicitly incorporates the behavior of another use case at a location specified in the base.

What is an << include >> stereotype in a use case diagram?

The stereotype “<>” identifies the relationship as an include relationship.

Can you explain extend and include in use cases?

Extend relationship adds up behavior sequence to the base use case. It is somewhat similar to the include relationship but the direction of adding behaviour sequence to the base use case is opposite. In the include relationship, the base use case incorporates the include use case.

What is an extend relationship?

An extend-relationship is a relationship from an extension use case to a base use case, specifying how the behavior defined for the extension use case can be inserted into the behavior defined for the base use case. It is implicitly inserted in the sense that the extension is not shown in the base use case.

What is mean by UML extension?

An extension is association relationship used to indicate that the properties of a metaclass are extended through a stereotype, and gives the ability to flexibly add stereotypes to classes and remove later, if necessary.

What is a UML class?

Classes. In UML, a class represents an object or a set of objects that share a common structure and behavior. Classes, or instances of classes, are common model elements in UML diagrams. Objects. In UML models, objects are model elements that represent instances of a class or of classes.