Author Topic: UML vs BPMN for detailed design documentation  (Read 6490 times)

Paolo F Cantoni

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UML vs BPMN for detailed design documentation
« on: September 20, 2015, 01:00:21 pm »
We're embarking on a process to create a unified modelling environment for Business Level Architecture (using ArchiMate with extensions), down to  physical modelling of real artifacts.

In business modelling, there's a change-over from ArchiMate to BPMN (for example as mentioned and documented in: : Mastering ArchiMate Edition II by Gerben Wierda).
However, when looking at more technical detailed design, we can describe  detailed program flow using UML activity diagrams etc. The EA help file has a section: Comparison of UML Activities and BPMN Processes  which seems to say that you can render any UML Activity diagram in BPMN, but not necessarily in the other direction.  That's my understanding.

Has anyone used BPMN diagrams for detailed program or computing process (as opposed to business process design)?

If so, can you share your experiences?
Any "traps for young players"?

TIA,
Paolo
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Geert Bellekens

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Re: UML vs BPMN for detailed design documentation
« Reply #1 on: September 21, 2015, 04:28:47 pm »
Paolo,

I've seen it in practice (overly detailed BPMN diagrams) and I found in that case BPMN was nut used anymore for BPM, but for functional modelling. Something which I think is still better done with use cases.

Recently I've seen a lot of companies that use a combination of Archimate (architecture), BPMN (business processes) and UML (functional and technical analysis), and it seems to work pretty good.

Each of those fields is usually analysed by a different profile, and each of these profiles seems to feel right at home with their respective modeling language.

Geert

Paolo F Cantoni

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Re: UML vs BPMN for detailed design documentation
« Reply #2 on: September 23, 2015, 09:45:28 am »
Quote
Paolo,

I've seen it in practice (overly detailed BPMN diagrams) and I found in that case BPMN was nut used anymore for BPM, but for functional modelling. Something which I think is still better done with use cases.

Recently I've seen a lot of companies that use a combination of Archimate (architecture), BPMN (business processes) and UML (functional and technical analysis), and it seems to work pretty good.

Each of those fields is usually analysed by a different profile, and each of these profiles seems to feel right at home with their respective modeling language.

Geert
Thanks for that Geert,
I guess my question wasn't as wide as your answer.  My question specifically, was: if you're using a UML Activity diagram, is there any problem with replacing it with a (as) semantically equivalent (as possible) BPMN Process diagram.  I'm thinking that I can use a specific subset of BPMN for expressing the same semantics of the UML it's replacing.

In our situation, we're not trying ot use 3 different  modelling methodologies, but trying to create a more unified holistic methodology that "dips its lid" to the originating methodologies.

I agree with you on Use Cases - that woudl be an example where we might extend our unified methodology to include the concept.

Paolo
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qwerty

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Re: UML vs BPMN for detailed design documentation
« Reply #3 on: September 23, 2015, 06:52:06 pm »
I have successfully used simple BPMN diagrams to enhance use case scenario descriptions. It's easily possible to use BPMN as replacement for ADs and to use additional features offer by BPMN by and by.

q.

AndyJ

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Re: UML vs BPMN for detailed design documentation
« Reply #4 on: September 25, 2015, 03:30:12 pm »
My preference is to have a jumping off point, where the modelling switches from BPMN down to UML (Use Case).

For example, on the BPMN diagram you have an Activity "Purchasing Clerk Creates Purchase Order" which is linked by a message to the "Purchasing System" lane, and an Object called "Purchase Order".

Any occurrence of a Human interfacing with a System is potential for a Use Case.

If you BPMN diagram has activities like (Add Line to Purchase Order) I'd suggest that it has gone down too low into the weeds.

I can see reasons why someone would like to create that kind of duplication across different modelling paradigms, but I'd prefer not to.

Andy
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Geert Bellekens

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Re: UML vs BPMN for detailed design documentation
« Reply #5 on: September 25, 2015, 04:07:23 pm »
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My preference is to have a jumping off point, where the modelling switches from BPMN down to UML (Use Case)

I'm with AndyJ on this one.

Geert

Paolo F Cantoni

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Re: UML vs BPMN for detailed design documentation
« Reply #6 on: September 25, 2015, 04:12:40 pm »
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My preference is to have a jumping off point, where the modelling switches from BPMN down to UML (Use Case).

[SNIP]

I can see reasons why someone would like to create that kind of duplication across different modelling paradigms, but I'd prefer not to.

Andy
Hi Andy and Geert,

Duplication is EXACTLY what I'm trying to avoid.  :D  I previously had to do that - trying to join ArchiMate and ISO11179 - that sucked!  This time around, I'm able to create a new MDG that allows me to mix and cross-over much more naturally.

Paolo
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Re: UML vs BPMN for detailed design documentation
« Reply #7 on: November 05, 2015, 08:43:21 am »
My experience is that BPMN is better than Activity diagrams for being able to estimate effort and cost  for things like security reviews.  People are also more likely to assume that an activity diagram is a flowchart.

Paolo F Cantoni

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Re: UML vs BPMN for detailed design documentation
« Reply #8 on: November 05, 2015, 10:59:37 am »
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My experience is that BPMN is better than Activity diagrams for being able to estimate effort and cost  for things like security reviews.  People are also more likely to assume that an activity diagram is a flowchart.
While I agree that UML Activity diagrams are more like flow charts than BPMN diagrams. Indeed, I often describe them to lay people as "flowcharts on steroids", I'm not clear what caused you to make that observation.  What is the impact of "lay" persons seeing activity diagrams as flow charts?

Paolo
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Glassboy

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Re: UML vs BPMN for detailed design documentation
« Reply #9 on: November 05, 2015, 11:17:11 am »
Quote
]While I agree that UML Activity diagrams are more like flow charts than BPMN diagrams. Indeed, I often describe them to lay people as "flowcharts on steroids", I'm not clear what caused you to make that observation.  What is the impact of "lay" persons seeing activity diagrams as flow charts?

Well if you end up with a page containing only actions and decisions there was no point doing an activity diagram :-)

Paolo F Cantoni

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Re: UML vs BPMN for detailed design documentation
« Reply #10 on: November 05, 2015, 11:43:20 am »
Quote
Quote
]While I agree that UML Activity diagrams are more like flow charts than BPMN diagrams. Indeed, I often describe them to lay people as "flowcharts on steroids", I'm not clear what caused you to make that observation.  What is the impact of "lay" persons seeing activity diagrams as flow charts?

Well if you end up with a page containing only actions and decisions there was no point doing an activity diagram :-)
Must be "thick" this morning (on bus on way to work), don't really see how your statement is related to your point re Activity Diagram vs Flow Chart.

Paolo
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Re: UML vs BPMN for detailed design documentation
« Reply #11 on: November 05, 2015, 02:01:17 pm »
Quote
Quote
Quote
]While I agree that UML Activity diagrams are more like flow charts than BPMN diagrams. Indeed, I often describe them to lay people as "flowcharts on steroids", I'm not clear what caused you to make that observation.  What is the impact of "lay" persons seeing activity diagrams as flow charts?

Well if you end up with a page containing only actions and decisions there was no point doing an activity diagram :-)
Must be "thick" this morning (on bus on way to work), don't really see how your statement is related to your point re Activity Diagram vs Flow Chart.

Paolo

My point is that Activity diagrams can carry a richer set of information than flow charts, for example what information artifacts (objects) are created and where they are stored.  This is useful information for things like security and compliance activities.

But it's a complete waste of everyone's time if your AD is really only a flow chart because all you're sowing is processes and decisions.  You haven't gained anything for the organisation by attempting to introduce a UML diagram type.

KP

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Re: UML vs BPMN for detailed design documentation
« Reply #12 on: November 05, 2015, 02:18:32 pm »
Quote
My point is that Activity diagrams can carry a richer set of information than flow charts, for example what information artifacts (objects) are created and where they are stored.  This is useful information for things like security and compliance activities.

But it's a complete waste of everyone's time if your AD is really only a flow chart because all you're sowing is processes and decisions.  You haven't gained anything for the organisation by attempting to introduce a UML diagram type.
I would say there is a place for simple diagrams - visual modelling is about managing complexity and simple diagrams can help in that - but that you should avoid simplistic diagrams. If an activity diagram is part of a rich behavioural model, it can be as simple as you like without being simplistic.
« Last Edit: November 05, 2015, 04:13:50 pm by KP »
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qwerty

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Re: UML vs BPMN for detailed design documentation
« Reply #13 on: November 05, 2015, 05:35:18 pm »
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But it's a complete waste of everyone's time if your AD is really only a flow chart because all you're sowing is processes and decisions.  You haven't gained anything for the organisation by attempting to introduce a UML diagram type.
Well, you improved marketing. And that's what marketing guys care for: not the product, but the marketing of the product. :P

But honestly I also used this marketing technique sometimes. A graphical representation of even simple scenarios often brings a different light on things.

q.
« Last Edit: November 05, 2015, 05:37:21 pm by qwerty »

Glassboy

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Re: UML vs BPMN for detailed design documentation
« Reply #14 on: November 06, 2015, 07:35:08 am »
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r simple diagrams - visual modelling is about managing complexity and simple diagrams can help in that - but that you should avoid simplistic diagrams. If an activity diagram is part of a rich behavioural model, it can be as simple as you like without being simplistic.

One of the things that contributes to the failure of architecture in a organisation is constantly introducing the business users to new methodologies or practices.  It creates a type of exhaustion.

So it's counter productive to show a UML activity diagram and explain how they work when you're showing nothing more than a flow chart with different notation.  Pretty much everyone you'll come across already knows the notation for a flow chart.

EA does flow charts - draw a flow chart.