How to represent Applications/IT systems in BPMN diagrams ?

Hello Michel,

the answer is simple: Don't do it. BPMN is a process notation. Application architecture is out of scope. Please refer to chapter 7.2 of the BPMN specification.

You wouldn't use a screw driver to drive a nail into the wall. You can try, but you will probably hurt yourself. Use BPMN for what it was made for: Description of process logic.

I can see 2 options for you:

1. Do an assignment of a "Task allocation diagram" to each BPMN task. Assign your IT systems to each step in those.

2. Use EPC notation instead. It can accommodate all the interesting business resources at a glance that you apparently want to meet at the activities. That is what this notation was invented and made for. There are variants of this notation that make it feel a bit like BPMN, e. g. table layout, horizontal layout.

Hello Michel,

got the wrong model type for the BPMN Tasks: You need "Function allocation diagram". The "Task allocation diagram" is for "Tasks", which is a concept in project management for processes with only one instance (projects).

Thanks again  M. Zschuckelt !

I see your points about Bpmn not being the right modeling language for our concerns.

Nevertheless, we're stuck as we have a lot of processes to model, Bpmn is required, and we need to keep track of which applications are used to perform some activities. After some discussions, we decided to go for the solution #1 : use the standard Bpmn user/script/service tasks, add the application performing the task as a task attribute. 

We're thinking about writing reports/macros/whatever

• to check that applications referred to in tasks exist as application type element,
• and create models to link the application type elements to the bpmn tasks (not sure about that, I have to check if a bpmn task may be used as a function in another diagram)

Hello Michel,

I tell you a solution I have seen where also a big process modelling initiative was performed in BPMN. In Collaboration Diagrams they exclusively used "sub-process" strictly at a desk-to-desk granularity and "Call Activity" for re-usable complex services. Inside the sub-processes (in BPMN process diagrams) they modelled user, service and manual tasks (one or very few steps, because all are performed in the same place at the same time). Only to those (service and user task) they assigned applications in function allocation diagrams (which they renamed as "task allocation diagrams" and caused my confusion).

The tasks and sub-processes of BPMN are definitely of type "function", so you can assign function allocation diagrams to them just like in EPC notation. Consider, if it is worth maintaining redundant information in attributes and objects. Maybe you consult an expert in Connect Portal configuration, if you can maintain connections to application system type objects in a fashion that feels like maintaining an attribute of the task. I heard of customizations that allow such a pattern, but I am not firm in these matters, if it is supported for functions.

According to the BPMN V2.0 Specification (Reference Guide), Pool Lanes can be used to represent Enterprise Applications/Software, see section 10.7 Lanes:

"Lanes are used to organize and categorize Activities within a Pool. The meaning of the Lanes is up to the modeler. BPMN does not specify the usage of Lanes. Lanes are often used for such things as internal roles (e.g., Manager, Associate), systems (e.g., an enterprise application), an internal department (e.g., shipping, finance), etc. In addition, Lanes can be nested (see Figure 10.125) or defined in a matrix. For example, there could be an outer set of Lanes for company departments and then an inner set of Lanes for roles within each department."
 

Another method is to use the Choreography Task element and repurpose the Participant B field for the system/enterprise application:

Hello Ian,

yes, absolutely correct: There are several options, what you can do with lanes, however the notation does not prescribe one or the other. Hence ARIS does not know, what your "Lane" is supposed to represent in the standard "BPMN Collaboration (BPMN 2.0)" model types. That's why ARIS introduced the "Enterprise BPMN Collaboration" model type, which allows you to represent applications, roles or org. units as Lanes. If you do that, everything placed inside the Lane gets the default connection type "supports" (for Application system type lanes) or "carries out" (for Role and Org. unit Lanes). However this mechanism does not support nested Lanes, e. g. if you nested an Application system type lane inside a Role lane you would only get the implicit connections from the tasks to the application system type lane. So in short, the possibilities to connect ressources in the Collaboration models are very limited. However, as a modelling tool for everything BPM it provides solutions for the problem: Either you use function allocation diagrams for every task to connect all the resources that the BPMN notation does not support (see chapter 7 of the BPMN specification) or you use the new content type modelling mechanism, which essentially does the same thing under the hood, but is more convenient to use, because you need not worry about the function allocation diagrams yourself.

Your idea of using Choreography is interesting, however

• ARIS does not support BPMN Choreography models
• "Repurposing" implies that you are optically misusing a notation for something completely different. A Participant is an object representing a participating process and the intention is to choreograph 2 processes. So even if ARIS supported this notation it would support "Participant" objects there, but no Application system types. To ARIS a Participant is an object and not merely an attribute.

Unfortunately, I haven't used my preferred and favourite BPA/BPM/modelling platform ARIS for quite some time. In ARIS EPCs, I used the Application system type element/symbol:

In BPMN, a Choreography Task element, is Lanes and Pools collapsed into a single object (11.4.1 Choreography Task). I tend to use Choreography elements more than Pools and Lanes to save real estate on the modelling "canvas" and printing to A4.

The approach (work around) I took was to represent an Enterprise Business Technology Solution as a Participant in the process (after all the system does “participate” in the business process), the same as you would using Lanes and Pools:

The above picture is taken out of the BPMN 2.0 by Example Version 1.0 (non-normative).

I do not understand your reference to Chapter 7. While I do agree BPMN is focused on human interactions, I do not see anywhere where representing an Enterprise Business Technology Solution is out of scope. I do agree that data and information models and Business Rules models that are managed by an Enterprise Business Technology Solutions are out of scope in BPMN.

Keeping in mind that BPMN does not specify the usage of Lanes, if representing an Enterprise Business Technology Solution was out of scope in a BPMN diagram, it wouldn’t be documented in section 10.7 Lanes, nor would OMG provide an example in the BPMN 2.0 by Example pdf.  

BPMN Participant Definition:

"A business entity (e.g., a company, company division, or a customer) or a business role (e.g., a buyer or a seller) that controls or is responsible for a business process. If Pools are used, then a Participant would be associated with one Pool. In a Collaboration, Participants are informally known as “Pools.”

In the Choreography Task element, I am representing the Enterprise Business Technology Solution as playing (Participating) a “Business Role” which in my opinion it is, it’s just not a human participant.

I do understand that the approach I took may not be applicable within some organisations depending on the EA, BizArch and business models.

Hello Ian,

Chapter 7.2 states, what is out of scope of BPMN. E. g. organizational modelling. The notation is focused on describing process flows. So everything else you add is by your own convention, e.g. using lanes for application system types or acting roles. And indeed these are use-cases suggested by the specification. Lanes are not important for the process flow. They are only layout elements for the reader and they may be rearranged automatically, if you want to express application system interfaces instead of change of responsibility.

Keeping in mind that the notation focuses on processes and their collaboration, my interpretation of a participant in that definition is that the pool (associated with a participant) represents the process boundary of the "business entity" such as company, division, or a customer. When we look at external entities like customers we mostly don't care about their process (although customer journeys are interesting, too, but only in the light of our process touchpoints). External entities and their processes are black box pools for our efforts and hence there usually is no distinction between the two. That's why often people come to think that the pools representing a customer or a supplier are of type role. Quite the opposite is the case: In BPMN we describe how our process (Pool) exchanges messages with their process (without detailing their process). It wouldn't make sense, either, to use the same graphical symbol (Pool), for two different concepts like processes and roles. In ARIS a Pool is just a symbol of an occurrence of a participant object. We make no distinction between the participant and its representation through a Pool. In my opinion a Participant is neither a human nor a piece of software, but a process! The Pool represents the boundary of a process/participant in a collaboration. Message flows cross the boundary to other processes. Control flow must stay inside the boundary. That's the core of BPMN.

If you are so fond of choreography models I suggest you place a feature request for Choreography support of ARIS. I once tried to mimick Choreography notation with ARIS symbols, but that is no fun. That notation is so different to what we normally do in ARIS that IMHO it will require special tool support.

HI MZ,

Many thanks for the explanation.

I suppose the elements used in the process model is dependent on the scope of the organisation's use case. If the organisation use case is to use BPMN for Executable Models (BPEL/XML) for interfacing with web services, APIs/RPA, humans, etc., using a service-oriented architecture (SOA) to interconnect and share data and security access to that data in a business workflow, then the organisation needs to use the elements for representing Participants/Systems/Events/Messaging etc..

This is partly why Chapter 2 Conformance (BPMN 2.0.2) provides guidance for vendors/users can claim full or part compliance or conformance with BPMN 2.0 of which there are 4 types of conformance:

1. Process Modeling Conformance
2. Process Execution Conformance
3. BPEL Process Execution Conformance
4. Choreography Modeling Conformance

Compliance with type 1 above also means support for Pool and Lanes, see 2.6 Summary of BPMN Conformance Types (BPMN 2.0.2) which is used to represent Responsibilities/Participants/Systems in a process model.

These days, at a minimum, I look for compliance with types 1 & 4 as my preference is to use Choreography modelling elements instead of using Pools and Lanes reducing the complexity and sometimes messiness e.g., overlapping connectors of the diagram. I find using Choreography modelling elements gives a much cleaner diagram. 

For organisations (usually very large enterprises) using SOA, ideally, compliance with all 4 types of conformance to maximise automation opportunities.

It's amazing the number of vendors that claim BPMN 2.0 specification compliance, but in fact do not satisfy the requirements as summarised in 2.6 Summary of BPMN Conformance Types. Having the Basic BPMN Modeling Elements as shapes to choose in business process modelling software does not mean compliance and support of BPMN 2.0.

Like you, I also would not mimic BPMN Choreography Modeling using BPMN Extended BPMN Modeling Elements in ARIS. However, I have not used ARIS (my preferred solution) in many, many years, so I am unaware of any improvement in its capabilities, functions and features.

And yes, I think it would be advantageous and perhaps provide a competitive edge if ARIS was compliant with Choreography Modeling Conformance (Type 4).

Hello Ian,

I invite you to make your case for Choreography Modeling Conformance of ARIS on https://aris.ideas.aha.io

I have not checked if there even is an existing request to that end, which you might support with your vote.

Product Management is monitoring all ideas posted there and that is also the place to collect support for your demand.

Maintaining relationships to objects in the fashion of attributes is supported in recent releases through the feature "Content type modelling".

Hi all

my initial post is a bit old, nevertheless here is how we are dealing with the initial problem : 

• Use BPMN to represent the business process activities sequences
• For every BPMN model create a matrix model : 
  • rows are the BPMN activities
  • columns are the IT Systems
  • each cell is filled with a relationship if the activity is done using the IT system ( we use the archimate "serves" relationship as we are using Archimate for our other models)

This has been done for more 300 Models. The end users however would prefer to "see" the IT System used to carry out the acivity without switching to another model (the matrix model).

"Content type (or satellite) modelling" seems a more user friendly way to respond to our user requirements. 

However this will impose us - Aris repositoy maintainers -  more work :

- learn another Aris module (content type modelling)

-  customize it to our needs (that is : not using the default FAD model for capturing activity/IT system relationship, but one who is compatible with our previous use of a Matrix Model)

- consider replacing all existing matrix models with content type modeling