Author Topic: Use Case: Use extension points in other diagrams  (Read 4215 times)

MrDX

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Use Case: Use extension points in other diagrams
« on: September 10, 2008, 10:57:30 pm »
Hi,

I have a use case diagram, some of them with extension points and extend-relationships. Each use case contains a sequence diagram to specifiy the the use case. Now, I want to 'call' the extension point.
For example:  'Build house' with extension point 'build garage' and 'build swimming pool'. How can I model a sequence like (with the extensions):
Build house{
  ...
  build_garage
  build_swimming_pool
  ...
}

Can you understand me?

Thanks in advance.

jeshaw2

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Re: Use Case: Use extension points in other diagra
« Reply #1 on: September 23, 2008, 02:17:21 pm »
I understand you; you need a different understanding of Use Cases [UC].

UC relationships (include, extend, etc.) are realized when the use case is published for a stakeholders reading.  Related use cases are not subroutines that are called at program execution time.
Verbal Use Cases aren't worth the paper they are written upon.

BioformLivesAgain

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Re: Use Case: Use extension points in other diagra
« Reply #2 on: September 24, 2008, 12:42:06 am »
A sequence diagram shows a specific pathway (scenario) through a use case, but a use case should describe a complete set of interactions covering many different pathways (alternate paths leading to success, exception paths leading to failure, etc.)

Then for extension points in an activity diagram I create an action or activity to represent the entry point into the flow.

If you have extension points, by definition you have more than one pathway, and thus the sequence diagram is NOT suitable.

Use a sequence diagram to map a SPECIFIC scenario (one pathway)

Hope that helps...