EA and Use Case 2.0 'Slices'

[Ian Mitchell]

I'm just starting to use the UseCase -> TestCase generation feature, as it makes EA REALLY useful for those who are using the new "Use Case 2.0" idea of 'Use Case Slices'. (see Jacobsen et. al white paper at http://www.ivarjacobson.com/use_case2.0_ebook/)

What I noticed is that the test case scenarios which get generated aren't all the possible paths through the use case, as described in Jacobsen's paper.

There seems to be one per Alternate, but you don't handle combinations of alternates.
So, if my Basic Path has alternates A1 and A2, I get test case scenarios for :
- BP
- BP, including A1
- BP, including A2,
- the A1 fragment
- the A2 fragment

but, I don't get BP including A1 and A2 (assuming that the logic of the use case allows the user to follow both paths in the same run of the use case).
I totally get why this would be: it's computationally nasty to cope with combinations of multiple alternates, and the user can quite easily construct these complex cases from the generated fragments, but I wanted to make sure that this was a deliberate omission. If so, then I'll explain to my users how they can make the complex cases themselves.

@Sparx - is this how it is ?

Also, it would be good, at some point, for EA to explicitly support the Use Case Slice idea, as it looks like you've done all the hard work, and it just needs a skin and a few graphics changes. UC2.0 looks a really practical way to use 'use case' ideas in the Agile world, so is likely to get more popular over time.

..and no, I don't want to write ANOTHER extension....:-)

[qwerty]

Not really new stuff. The problem here is (like generally for UML model) how to model these slices. It's a part of the system you need to identify. And then you need some mechanism to handle the transit from the current stage (slice) to the next one. This is the main problem and I don't see a solution for that. There is no smart way to cut slices out of a model. Certainly there is a huge demand (see the discussions here on the forum). But designing a solution is something to think over for a couple of eggheads.

q.

[Ian Mitchell]

A first step would be to use the code which creates 'Test case Scenarios' and make each 'Slice' into an Element. Then it can be linked to other stuff more easily. Not rocket science.
Creating the definitive list of those slices from a set of Use Case structured scenarios is one of those problems Sparx should give to a recent computer science graduate: they would know!

[Huub]

Hi Ian,

I really enjoyed reading your posting on EA and Use Case 2.0 'Slices'
https://groups.google.com/d/msg/sparx-enterprise-architect-general/UuwnD7m6kcA/kMiG3VtcO0wJ

Did you find a way to deal with Slices/Use Case 2.0 in EA?

As far as I know it's still possible to create a trace from Requirements to Use Cases, but not to any level deeper within UC's (e.g. Requirement to a specific Alternative flow). Very unfortunate for use in a project environment where several people are happy working with ('a kind of'..) User Stories and several others like me would like to take that to another level  by working towards a more Model Based approach in order to create a single truth to be used from several viewpoints/stakeholders.

Any insights on how to deal with this with EA would be welcome. Although for many people in the company I work for EA has a (too) steep learning curve I believe the results of a good approach van be rewarding.

All the best from The Netherlands,
 Huub van Burken

[Geert Bellekens]

Hi Ian, Huub,

I was at a Use Case 2.0 conference in Amsterdam this week and we saw how the NS (dutch railroads) implemented the use case slice idea in EA.
We didn't get much details but I think Jordi Reineman will be happy to elaborate if you contact him.

We are also planning to get someone from the NS to explain how they use EA at the next EA User Group event in Brussels (2015-09-18)

Me personally I'm not convinced we should store the slices themselves in EA. I try to make a difference between project information and product documentation. Project information is short-lived and can thrown away after the project is finished.
Project documentation is something we like to keep for the whole lifetime of the product.

I tend to keep only the product documentation in EA and keep the project documentation elsewhere.

Slices are more project documentation so they wouldn't necessarily appear in my model.. But of course project documentation should still link to elements from the product documentation (model) to keep full traceability. So I would still need to be able to determine all elements (from the model) that were delivered in a slice.

Geert

[Huub]

We're some years further and via a google search I found my own comment in this threat  . Anyway, do you guy's have some more good resources to read and learn from? (I'm still interested in the subject. Up till now we're kind of stuck in the middle leaving the 'product documentation' with parts of the 'project documentation'. Personally I see the necrsssity for speed during project time but also need for better functional documentation at later moments, especially when we tend to forget details and people leave the knowledge domain)

[jfzouain]

Hi to all

Wrote an eBook about all this.
About keeping the PM stuff else where, it all depends of the company.
Have used EA for requirements, use case, activity diagrams, test cases and project management, all together, and it works great.
My 2 cents.

[wivel]

Brings back memories.

Worked with Ivar in the good old days of Objectory and the early days of RUP and what later became Use Case slices, we called Use Case Scenarios back then in the early 2000's

Slices are a must in the test analysis and design, to ensure that you don't waste time testing combinations that will never happen and/or contain mutually exclusive flows.

Henrik