Use Case Scenario pre/post conditions

[PaulStevenson]

Is there a way of specifying individual pre/post-conditions for structured scenarios in a Use Case in EA?  I have a few for which post-conditions in particular differ depending on the alternate chosen.

Thanks for any help you can give me.

[Geert Bellekens]

Paul,

I don't think you can. We use a naming convention to define pre/post conditions for specific scenario's.

Geert

[vjr]

Go to your use case properties, choose Constraints tab, select Pre-condition or Post-condition from 'Type' drop-down. Type the pre/post condition details in the 'Constraint' edit box.

Edit: just read your post properly. Does UML allow that? It seems a bit of overkill.

[Geert Bellekens]

AFAIK use case scenario's are not UML defined artifacts, so attaching constraints to them would be outside of standard UML.

Geert

[PaulStevenson]

Hi thanks for your help everyone who contributed.  Is it overkill?  I would expect each end-point in a use case would have a different set of postconditions.  

We've got around this using the scenario descriptions now.

Thanks again!

Paul

[vjr]

It's true that scenarios are not defined in the UML. My interpretation is that the 'pre-condition' of an extension use case is the condition (constraint) on the extension, if present.

From section 16.3.3
"• condition : Constraint [0..1]
References the condition that must hold when the first extension point is reached for the extension to take place."

This seems to be modelled in EA by the Scenario's name, which is shown as the guard in an activity diagram. An extension use case isn't meant to exist on it's own, so I'd imagine it shouldn't have pre/post conditions. But, whatever works for you