Sparx Systems Forum

Enterprise Architect => Uml Process => Topic started by: Screwtape on April 27, 2016, 08:57:22 pm

Title: Specifying Overriden Steps in UC Specialisation in EA
Post by: Screwtape on April 27, 2016, 08:57:22 pm

At the risk of opening another huge debate on whether specialisation of use cases is appropriate, I'd like to ask a very specific question about documenting steps.

I have a base (non-abstract) UC with 4 steps.

1 - Get criteria
2 - Expand criteria
3 - Do search with criteria
4 - Filter results

The specialised UC will do 1, 2 and 4 exactly as the base UC, but will override step 3.

How would this best be represented in EA?

I have a BPMN process diagram for the base UC, but repeating the diagram with only the changed step seems to defeat the point of generalisation.

Having searched the web for examples, all I've found is a number of very trivial examples of what generalisation is, and how to represent it on a UC diagram, but nobody has shown any good examples of what the UC description and steps text should look like.

Any pointers or suggestions would be welcome.

Thanks!

Screwtape.

Title: Re: Specifying Overriden Steps in UC Specialisation in EA
Post by: Geert Bellekens on April 27, 2016, 09:07:59 pm

Whenever I allow Use Case Generalization I usually advise to make a type of "abstract" use cases that have a description and pre/post-conditions, but no scenario.
Each concrete sub use case then has to define it's own complete scenario.

Mostly for the reason to keep the sanity of my analysts and even more so their audience, "the business".

Doing inheritance and overrides like we are used to in classes is simply too technical and complex for the business who has to validate our use cases.

Geert