OR XOR AND relationships in use cases

Hi there,

in class diagrams, it is possible to have AND, OR, and XOR relationships between classes and/inherited classes. Is this also possible in use cases?

cheers,
ten

Hello ten,

It’s not a normal case to model AND, OR and XOR relationship in class diagram since class diagram is only modeling the static structure of the system. But still you can model this via the Constraint connector (use the Constraint connector to link up the association and specify the AND, OR and XOR relationship). For use case diagram, since use case is for modeling the user goal on a system, you will not model the user want to do X or do Y on a system, but both X and Y are user’s goal. If you require any further information, please do not hesitate to contact me again.

Best regards,
Rain

Thank you Rain. The case I am having actually deals with ‘generalisation’ i.e., there’s a use case that has basic preconditions. 4 functionalities I need to model thereof. Hence, the functionalities can not be inclusive. That’s why I thought of giving constraints.

Hello ten,

For this case I think you should use the extension point of use case. The extension point identifies a point where the behavior of a use case can be augmented with elements of another (extending) use case.

Best regards,
Rain