http://www.bpmn-selftest.org/

I made it to rank 14 of 394. However I wonder who the 13 were, that were better . So give it a try, maybe you can beat me. The test is anonymous however.

Nevertheless I want to share what I thought when I saw the models. They were quite complicated. I think if models are as complicated in a real project as those in the test, then something went terribly wrong in the first place. I agree, that it is fine for a research project to use artifical complicated models, to find out more about human model comprehension. And I am very interested in the research result. But models must be much simpler than those.

Simpler models could be reached by limiting the scope of one model – i.e. splitting it up in different parts, using submodels for example. As far as I remember human comprehension can assess 7 items at once, not more. So in essence I think a model should not contain more than about 7 important steps.

Also it can mean to model only the most important cases and model the special cases in a different model.

And it can mean to question, if BPMN is the right model language for the purpose chosen. I know that BPMN is popular and becomes even more, because it is a standard. But in my eyes the question remains, if the task flow oriented modeling it does is really the best way to do it. In my eyes it should be evaluated as a result of this research project, if goal driven and constraint based modeling would not result in much easier models.

Elaborating more on what I said before about loosely coupled processes, I want to emphasize today, that the cut of the processes is of major importance – i.e. which parts are loosely coupled and which parts are tightly coupled. Furthermore if process parts are loosely coupled, it is of big importance which process parts are public and which are private. Public process parts constitute a contract, that the other participant can rely on (when to request, when to confirm), while private processes are only needed within the operations of one participant’s organization – for example an approval or a special form of approval that is irrelevant to the other partner. This has these benefits:

• Flexibility: It is possible for one participant to adapt the private process to changes as business requires it without the need to negotiate with the other partner, as long as the change still complies to the public process.
• Stability: The participant can rely on the behavior of the opposite participant, even when the opposite participant makes changes that comply to the public process.
• Visibility: In Process Monitoring internals are not visibible because they should not. It is a decision of discretion which parts of the process should be visible to other partners. However I believe that BPMN 2.0 might be amended for this purpose, because for this it might be necessary that also non-communication activities can be part of a public process.
• Decoupling: The number of private processes that comply to a public process needs not to be multiplied with the number of choreographies, that comply to a public process. Say you have 3 choreographies that you want to combine with 3 private processes. Then without decoupling you have 3*3=9 process models. With decoupling you have 3 + 1 + 3 = 7 process models.

It is important to understand, that the Choreography is an abstract process while the private process is a concrete process – i.e. can be executed by a process engine and has process instances. So the Choreography Model will never be executed by a process engine. It is the summary view of the participants. It never proceeds on it’s own. It proceeds, if one of the participants proceed (as far as the public process is concerned).

If you ever tried to build a central process with process instances that decide about the message flow, you might have tasted how difficult that is. For simple processes this might still be possible. However you always find these difficulties:

• Either the central process does not have enought information to decide – and that are business decisions in the end – or
• The central process needs to know nearly everything.
• As soon as information reaches the central process by means of messages, it is already outdated (because the sender might have evolved in the mean time).
• Also in many decisions it is necessary to involve humans, not just rules.
• If humans are involved, they might not only to decide left-right, but regroup – solve differently (e.g. create return instead of lowering delivery quantity).

This all leads to the conlusion, that I have made for myself: If there is a middle tier, it needs to be a full fledged business application in the end. With business objects, UIs and the like.

Then we have 3 partipants instead of 2 – which is fine. Then we have 2 Choreographies between them, which are still abstract.

First: What is the purpose of BPMN?

1. Description of as-is processes within a company and cross companies
2. Using the models for subsequent system development. The model is the high-level specification.
3. Execution of the model (for example in Appian Anywhere) – probably translation into another execution language like BPEL.
4. Model driven development of systems.

If we want to reach and achieve the fourth step, it is clear, that the execution semantics must be clearer as before – unambiguous.

On the one hand it is required to have “soft” models in the description of as-is models and also shall-be models. This will be so in all future. But especially the connecting of business domain models with system models within a holistic model cycle is a new level of effectiveness that we set our hope to.

In my opinion, this hope is not in vain.

Furthermore a complete meta model is needed for model exchange. This is – in my opinion – overdue anyway.

Why do we model at all? We want to utilize and connect flexibility with quality. This is reached by transparency. Only by transparency it is possible to execute the needed quality assurance on this level. If this is connected with model execution or model driven development, this is even better. We have laid the foundations.

This sounds quite enthusiastic. However I am a notorious BPMN critic. Even now more than enough critics comes to my mind. However I am exhilarated what we have reached within the scope of BPMN 2.0. We have made enormous progress in some key areas. I will elaborate on this in further blog posts.

So if in this example the incomplete model is validated against the meta model, then it fails, because the meta model requires at least two participants for the conversation node. However it makes completely sense to have the cardinality 2..* in the metamodel, because there is no meaningful Conversation without at least two participants. A possible solution would be to water down the metamodel. This is not discussed for BPMN 2.0, but may be for XPDL.

So in this watered down metamodel the participants cardinality is only *, allowing for 0 participants as well. The validadion succeeds, but the semantic suffers. Furthermore the check has to be done whatsoever at some stage. So watering down the metamodel is not a good idea in my view. Instead the solution should be a model lifecycle.

In this proposal the model itself has a lifecycle, which can be active or inactive. If the model is inactive, the validation reacts gracefully against the metamodel. Only if the model is active, the validation fails, but this is indeed intended. So it is unter the control of the modeler, if he wants the full strength of the validation or not.

Such a model lifecycle is not planned in BPMN 2.0 as far as I know, but I think it is a good idea and should be considered. There is a MOF 2.0 Facility and Object Lifecycle Specification that might be considered to be used in order not to invent something new that exists already.

In the BPMN 2.0 Spec there is a proposal, that builds on a generic OMG proposal, which is not finalized and which will be standardized independent of the BPMN 2.0 standardization.

In this proposal the idea is to have a Diagram Interchange Model independent from the Domain Model, which is in my opinion, a good idea. It is generic, so that other diagram types could be modeled. The diagram validation is done agains a so called Diagram Definition Model, which is also new. The Diagram Definition Model defines, which Attributes a Diagram Interchange node or connector can have, the allowed references and additional (OCL) constraints. Furthermore each Diagram Interchange node or connector is refers to a Domain Model class – in this case a BPMN Task or Gateway or Sequence Flow for example.

Advantages I see:

• Seperation of Model and View – Model maintenance
• Multiple Diagrams for the same underlying BPMN model are possible
• Generic format for different diagram types – tools can use synergies

Disadvantages I see:

• Tools vendors can not use XSD validation. They have to implement the validation against the Diagram Definition.
• The constraints of the Domain model (e.g. Sequence Flows can only be connected to …) must be repeated in the Diagram Definition Model.
• Grafical Attributes (e.g. line thickness) must be repeated as per modeling element.
• Attribute Format (name / value) too generic in my view.

The XPDL Format used to include the Graphics Info into the Elements of the Domain model.

This is simple and straight, and current tools support it, but has the disadvantage, that it is not possible to have one modeling element (e.g. one process) appear in different diagrams. Instead, the modeling elements must be repeated as per diagram, which has many disadvantages in model execution, analysis and model driven development. The Signavio modeler, which was discussed at the meeting, follows the same approach. However it is good as long as only diagrams are drawn for visualization purposes.

Because the BPMN Digram Exchange Proposal was too generic for some, Bruce Silver proposed an BpmnDI.XSD for a concrete XSD validation.

This approach repeats basically all or many BPMN domain modeling elements. This of course is the disadvantage, because it is but a redundant repetition of the already defined domain model. However it is no complete repetition, because the gateway type for example is not included. So a tool must look into the domain model anyway to render the gateway.

Within this discussion it came to my mind, how the GMF (Graphical Modeling Framework) solves this question. I think it is well worth to have a look at this approach, because I think it may be a good compromise.

The GMF defines a Grafical Definition Model, which only defines Shapes. This is simple to understand and straight. Then it defines a Mapping Model. Within the mapping models, nodes and connections are grouped as needed. For example it defines, that there is a node lane which can contain node Activity and Sequence Flow. As a followon the Acitivty node is connected to the Activity domain class and the Shape, that descibes how an activity should look like. The shape can be re-used, which is an advantage of the BPMN Diagram Exchange Approach. The Structures of the Diagram is already contained in the Mapping Model, so it can be serialized to XMI and XSD, which is also an advantage. However still the diagram logic is separated from the Domain Model, which is an advantage over XPDL. And it is a very generic model, which is an advantage over a mere BpmnDI.xsd.

I personally worked with the GMF, and found it quite practical. I am not proposing to use GMF per se, but maybe the approach should be further considered.

I must admit, I was a little bit surprised about the result. For me BPMN is not flexible enough and it has too many modeling elements. While this is not the majority opinion, a grave minority has the same opinion.

Some comments:

I think BPMN is great – but we just had to add on a few bits to define value add and non value add activities so that larger maps had more to narrow your focus on areas that need attention

Alan Crean, CEO @ Process Master

I agree that this is necessary to not overload the modeler with too many modeling elements.

Flexibility is a vague term that can mean many things in different situations. I would define flexibility as the ability to make changes over time as needed to respond to changes in the situation. In order to be flexible, there have to be constructs that afford the kinds of changes you will need. For instance, flexibility implies some form of control. A common pattern might be that parts of the process diagram are controlled by different people. There is no consideration in BPMN for specifying who has control over different parts. Instead, there is a built in assumption that the entire diagram is designed and maintained as a whole. That reduces flexibility.

Different people controlling different parts of the process diagram is definitely a very important part of the flexibility requirements I see. There is no concept in BPMN for this. It may well be, that it is not possible to add this concept later, because of the current semantic of BPMN.

I consider BPMN still more as a (high level) programming language for automated processes which provides rather poor support for flexible human processes.

I agree.

Just one examples of too less flexibility: Consider a process where one task can be executed by different roles (e.g. via delegation). In which Lane should I place the task? Should I show it in the “Default”-Lane? Or a copy in any other related Lane? Or even draw it across multiple Lanes?

While I know that Lanes are just a graphical partition of the process and we could easily address the problem via performers (BPMN 2.0), this is not a graphical solution. Many users (and tools too) use Lanes synonymous to performers.

Interesting case.

I guess it depends on the tool you use. We have created a new tool generation which hides the complexity of the BPMN notation against the user by using intelligent algorithms which support a highly efficient modeling process.
Our BETA was anounced on Nov 10. Innovator for Business analysts will be available shortly. C. Bergner.

It is worth trying. However my doubts are that certain limitations in the metamodel can not be overcome by a tool. However a tool can improve.

We feel the technology driven approach of BPMN when it comes to high level process landscape description. This seems to be out of scope at least in the BPMN 1.x standard.BPMN is good for visualizing low level processes that ar candidates for workflow implementations.

I agree.

It’s really interesting to see your opinion. In my opinion BPMN has a workflow modeling background. That’s why it is good for workflow type of processes. However there are a lot more of other processes.

Suddenly I felt like in a lively discussion about what I thought for some time about the inflexibility of BPM models (what if the approver is on leave?), the ad-hoc nature of real processes (like in a court trial) and the small amount of system support for these.

Yes, Business Process Modeling to a degree rests on the assumption, that there are repetitive procedures that are triggered by a business transaction, and which is described in terms of which steps to execute as a result of it. Like a machine.

Did you ever wonder why there is so little standard software for startups – or business process models? If it where a standard process, it were not a startup. The driver in the seat hopefully is the founder of the startup, not a process.
I agree to the observation, that there are much more processes like this all over the place. And maybe there should be even more again, reverting the feeling to be but a cogwheel in the engine, but a responsible contributor – even for the benefit of the whole.

Still, what we need to work effective is system support for

• our information
• Collaboration and Communication over the information
• a clear status of all of the process and all parts of it
• Decide about next steps as you go
• Decide about required information as you go
• Decide about groups and access policies as you go
• Decide about information structure as you go.
• Overview and Tracking

Only to mention the most important ones.

This is not what you can to with BPM . Therefore we need a new breed of software which is not BPM, even if it is related to it.

I want to mention two things, that were not or not deeply discussed in the meeting as an additional contribution and defence of what I said.

First: Even with all the ad-hoc type of processes it is clear that over time some of them evolve in standard processes, which is a good thing. Because that is the time to earn money for the process owner. So there must be ways to

• pick best practices and develop them into standard processes
• re-design a bunch of local best practices into a global standard process.
• impose constraints of a standard process on the business

All of that as you go – i.e. without interfering the running processes.
Which is easily said – sounds a little like marketing buzz – but certainly challenging in terms of technology. But I wouldn’t say it, if I didn’t think it’s possible.

In Process design and re-design I disagree here with Max J. Poucher’s more philosophical statements about evolution. I do not believe as much in evolution as an unguided process as he seemingly does. I believe that redesigning processes as a whole makes them more effective, and more rewarding to everybody if done right.

Second, I think that we need is a seamless integration (A word that you first learn in marketing) with structured processes – be they classical workflows or classical ERP processes. In my opinion there is much ROI to be found.

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