Use case- generalization and extend

[Chloe Jones]

Hi

I'm slightly confused about the difference between generalization and extend within Usecases.

My understanding is:

extend- this is conditional and this use case only used when a condition is met. The base use case runs and then if a condition is met within this, the extend use case will be called. ie like an IF statement

eg. Base use case- Authorise payment, a use case may extend from this called Process failed payment

generalization- this is like a parent and child relationship within classes. The child is a specialized form of the parent.

eg. Pay for Item may have a generalization Pay for Item by Credit card and another generalization Pay for Item by Debit card

Please can someone confirm whether my understanding is correct ... as I've also seen places where this has been described the opposite way around. Has this changed in UML 2.0?

[Peer Reynders]

Welcome to JavaRanch,

Please check your private messages.

See also: UML: generalization vs. extend use case