Author Topic: Actor and use case generalization question  (Read 1099 times)

Robert_N

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Actor and use case generalization question
« on: February 02, 2010, 12:59:23 am »
Hi,
i have a UC Diagram where i got two actors:
 Viewing User and Logged in User how is a descendant to the Viewing User.

The Viewing user has som Use Cases and a Use Case "Create Account". The Logged in User can of course "execute" all the Viewing User use cases but not the "Create Account" use case. How do i show this on a diagram, or do i have to rethink my generalization and change my diagram and actors.


Geert Bellekens

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Re: Actor and use case generalization question
« Reply #1 on: February 02, 2010, 01:26:37 am »
Robert,

I think you are ok there.
You said that the "Logged in User" is a specialization of the "Viewing User".
In that case the "View xxx" usecase is "used" by the "Viewing User".
Because "Logged in User" specialises the "Viewing User" is inherits this "use" relation and so it can also use "View xxx".

The "Create Account" usecase however is only used by the "Logged in User" so it cannot be used by the "Viewing User".

Geert

KP

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Re: Actor and use case generalization question
« Reply #2 on: February 02, 2010, 09:28:37 am »
Geert, I think you've misunderstood the problem but Robert appears to have edited the diagram to show more clearly which use case is the "Create Account" one.

Robert, I would simply define a pre-condition on the Create Account use case to say that the user must not be logged in.

HTH
The Sparx Team
support@sparxsystems.com

Geert Bellekens

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Re: Actor and use case generalization question
« Reply #3 on: February 02, 2010, 06:10:14 pm »
Yes, indeed, I misunderstood.
Precondition seems indeed the best way to go.

Geert