Relationship between Activity(BPMN) and UseCase

[Michel777]

Hi,

our Processes (BPMN) and Use Cases have been modeled.  Also the relationships between Activities and Use Cases have been defined, vie realionship Matrix.

The only thing, what is missing: the visualisation of those realtionships.

How to let show all the relationships between two models ?

Remarks: in case of placing an Activity on the UC-Modell, the relationship between Activity and UC is displayed. But not in the case, when we put UC on an BPMN Diagram.

Thanks a lot un advance,

Michel

[qwerty]

Well, not to discourage you but thinking about those basics before modeling all the stuff would have been wiser. So I have no answer in that case.

Maybe for your next project here is what I would have done: Use the use cases as container for activities and placing them in a context diagram (composite for the use case). This way you do not need any relation at all since it's modeled through structure.

q-

[Michel777]

We need relationships, because one use case can refer to more the one cctivity. There is it not only use cases, which refer to the activities, but components too. Actually we are going to orchestrate different components by referring components to the activities. It seems to be the only way, put all elements (activites, use cases, components) in to the  same modell, to mix apples and oranges together.

[qwerty]

As I said: use structure instead of relations. Activities inside UCs are logical and easy to realize.

Now for the next step: create a collaboration realizing the UC and put the behavioral description inside. If you have components these can go to a static model description which can be used by the collabs. Actually I'd use a CIM/PIM/PSM structure where the UCs, collabs and classes are located in the PIM and the components in the PSM. A good structure is the best way to not mix apples and oranges. The best, of course, is to have a cut through with all elements right from the beginning (or as early as possible).

q.

[Ian Mitchell]

I agree with Michel777.
Having a BPMN Activity connected to a Use Case seems a much more flexible solution than what I think Querty is suggesting, which seems to be to make the Activity a child of the Use Case. This isn't flexible, and doesn't allow, for example, all the BPMN 'stuff' to live in one part of the model, and the Use Cases in another.

 I've just tried this - relating a BPMN2.0::Activity to a UseCase with a simple 'dependency' relationship, and it seems to appear OK on both diagrams: dropping the UC onto the BPMN diagram, and the Activity onto the UC diagram.
EA (mostly) doesn't care which elements appear on which diagrams: if two elements are on the diagram, and they have a connection, unless you say otherwise, EA will connect them.

I'd also like to disagree with Querty on another point (I feel brave today!): working-out all these kinds of meta-model structures and links in advance is almost impossible: only as your project develops can you decide what connections are useful. That's the beauty of EA: you can add them, and modify existing ones, as your model gets bigger.

[ken.norcross]

We relate BPMN Activities to Use Cases also. The Use Cases in turn have scenarios which can be turned into Activity Diagrams containing UML Activities.

The idea of an Activity as a child of a Use Case may be referring to this case were (at least in Sparx with the auto generated Activity diagrams) the Activities by default live as children of the Use Case.

I think everyone has to be clear if they are referring to BPMN Activity or UML Activity.

We also create separate diagrams to map the BPMN Activities to Use Cases rather than clutter up the BPMN process diagram. The diagram itself is not very useful, it is just a way to easily create the relationships. Once the relationships frpm BPMN Activity to Use Case are defined, we walk these relationships when we produce documentation.

[qwerty]

I feel brave today!

Daredevil!

I wouldn't claim my opinion is the only correct one. It's just my experience which was speaking. A cut-through does not mean you have everything in advance. But you have benchmarks at the most prominent places. And these help to navigate through the swamp - even if someone turns on the fog.

q.

[Guillaume]

A dependency can be created between any 2 elements within your project, and will be displayed onto any type of diagram including BPMN.

You could define & use a stereotype on dependency links to identify specific type of links between a BPMN activity and a UC.

This lets you trace links e.g. between activities from a business process and use cases from your analysis model.

Ref the question :"How to let show all the relationships between two models ?"
=> you can create a dedicated diagram to drag&drop both your BPMN activities and UC so all links will be displayed.
EA provides all sorts of features to manage and extract your project traceability.

Guillaume