Using use case elements in two diagrams

[ryanc]

All,

I'm seeing the tool do something that would normally be useful however in the way that I'm trying to use it (probably incorrectly) I don't want it to help out.   Basically I created a use case diagram.  Now I'm trying to create an activity diagram using the same (linked) use cases to show the flow or order that they normally would be performed in.

However when I do this it has created the links between the use case elements that I create on the Activity diagram on my use case digram.  I don't want those same connections to show on the use case diagram.  

Is the best way to get around this just to create an activity element for each use case and then use that on the activity diagram?

Or when I drag the use case element onto my activity diagram shall I tell it to create as an instance rather than a link?  

I just tried doing this in two ways?

1.  Already had the use case on the activity diagram as a link.  I used the right-click popup window and told it to convert classified to instance.  When I do this I get the ":" in front of the name and another element showing up in my package in the project view.  

2.  If I drag the use case onto the activity diagram and tell it to paste "as Instance of Element (Object)" then I don't get an extra object in my project view tree.  I also don't get the colon.  

These two ways of doing this seem to be the same but aren't visually acting the same.  So I'm guessing they're not.  I'm also not seeing the connections made on my other diagrams that are using these use cases.

Thanks!

Ryan

[mchiuminatto]

Hi Ryan

I think what your are trying to model is a busines cycle, which goes across more than one use case.

I recommend to use the Eriksson-Penker extensions and add some tagged values to show what use cases are involved in each business process.

As far as I know there's no notation and semantic in UML specification to model sequences between use cases. Mybe I'm wrong, but I don't think so.

As an alternative you can model higher level (business level ) use cases (Alistair Cockburn - Writing Effective Use Cases, refer to white, cloud and kite levels) and model an activity diagram, also refering the use cases that are user-goal oriented (using tagged values). Those higher level use cases are mentioned in RUP as busines use cases


Hope it helps

[thomaskilian]

Marcello is right in what he says. The flow of use cases is best represented in Eriksson-Penker diagrams (or flavours of them) in an extended class diagram. The activities in one use case can be described in one or more activity diagram(s) for basic and alternate scenarios. You would not drag a use case onto an activity diagram, just the activities inside (which you don't drag there but define them while drawing).