BPMN Data Object traceability to Data Model

[Tim Hosking]

Hi,

I am looking for some advice. I am doing a business process model and I'm including data objects. I want to then link the data object to one or more entities (classes) in my data model. This provides good traceability and completeness checking, both for the data model and the process model. In other words, when doing a process model, if I find there is no entity in my data model to satisfy the process, then I have discovered a gap in my data model, and vice versa.

So, any advice on the best way to link the data object to one or more data entities?  

Thanks,
Tim

[Helmut Ortmann]

Hi Tim,

you can establish a traceability by means of dependency. You may choose your own dependency stereotype <<trace>> or so to make it clear and unique. You may also stereotype source and target of the dependency.

Than you can check the model against your rules by:

• Search data objects which have no entities (EA Search Engine)
• Write a validation to check your model against your rules
• I think there are some third party products which are able to verify your rules by means of configuration
• Relationship Matrix is often a good solution to mantain and verify traceabilty
• etc.

Helmut

[Tim Hosking]

OK - thanks for that. I guess the matrix is the best to use?

Thank again.

[Helmut Ortmann]

Hi Tim,

I think it's the easiest way to start.

If you have a very complex model you may think about other solutions.

Helmut

[Ian Mitchell]

I'd either just use the Class in the BPMN diagram (I know, not 'pure' BPMN, but it's a notation not a religion...)
or
if you think you'll have a 1:1 match between BPMN Data Objects and Classes in a Class model, make the InstanceClassifier of the BPMN Data Object into the Class. That way changes in the Class name will cascade through to the Data Object.

[Jacob Vos]

Like Ian, I also use UML Classes as Data Objects in BPMN. Luckily Sparx offers this cross relations between concepts of different approaches (BPMN - UML).

Via a matrix you easily can see the relations.

So the relation is not BPMN nor UML. Issue that I had when applying formal BPMN, is that a Data Object exists for the duration of the process. And that's not what I wanted to express.

[Jacob Vos]

One additional remark about the proposal of Ian to apply instance classifiers. If you do that, then you cannot see at the UML class the data associations you defined with BPMN activities.

For example, you have the UML class 'Contract'. When you put links on BPMN diagrams to this class and define data associations to and from activities, then at the relationships of the class all data associations are shown.

But if you add BPMN Data Objects to diagrams (also called 'Contract') and set as instance classifier the UML class 'Contract', then at the UML class the data associations with the activities aren't visible.

Maybe it's possible in another way to get the data associations via instances of the UML class - I don't know.

[Tim Hosking]

Hey guys,

Thanks so much for these very helpful posts. I had indeed wondered both about using InstanceClassifier and just putting the class on the diagram, and what the pros and cons of each were.

I think I may well go with linking the class directly to the diagram, rather than using the Data Object (taking the point in BPMN it is only available for the life of the process). My model is strictly a descriptive one, intended to communicate to business how the process and data work together, but also for developers to see what data should be used, and therefore what data access/updates are required. I agree Ian - it's not a religion.  

The only downside is that I may need to refer to more than one class for an activity. For example, if I have a typical Order and Order Detail structure in my class diagram and the process is to "Create Order", then I would have to associate both classes to the process, which might be messy in complex processes. Or, I could just link the "parent" class of "Order" to the process and thereby imply that "Order Detail" is involved. Or, I could create some kind of container class that links to both "Order" and "Order Detail", which is what I was thinking the Data Object could be.  

I suppose the other choice is what Helmutt suggested - use Data Object and then create <<trace>> relationships between it and the one or more classes it represents.

Thoughts?
(Thanks so much for taking the time to think about this.)

Tim