BPMS Watch: What if BPMN Were a Modeling Language?

Registration is free. Login or register to view/download this content.


Business Relationship Manager - Product Lifecycle Management, Chevron Corporation

Lacking support for fundamental concepts like human tasks and subprocesses, BPEL has become a favorite whipping boy of BPM vendors and consultants. But for all its faults, BPEL enjoys something that BPMN advocates can only dream about: an XML storage and interchange format that makes sense. It’s often said that BPEL is an XML language not a graphical notation, but the reality is that graphical BPEL design tools all use more or less the same notation, based on a simple mapping to native BPEL language constructs: Receive, Reply, Invoke, etc. BPMN has a standard notation, but still lacks a standard storage and interchange format consistent with the fundamental goals of BPMN itself.

I’ve been thinking about this recently with the recent announcements from OMG that the “official” XML format for BPMN, based on OMG’s new Business Process Definition Metamodel (BPDM), is in its final stages of ratification. Besides BPDM, Intalio has developed an alternative XML format for BPMN and has contributed it to the Eclipse Foundation. And let’s not forget XPDL 2.0, the Workflow Management Coalition’s reworking of its old process interchange warhorse to encompass various pieces of the BPMN spec. But to me, none of these proposals is as satisfying as BPEL’s approach, which makes the XML format closely match the terminology and semantics of the process constructs, their target audience, and business purpose.

One possible reason for this is that BPEL is considered a “language” while BPMN just a “notation,” i.e. a drawing format. But any student of my BPMN training – or anyone who has glanced at the BPMN spec – can tell you that BPMN is far more than a Visio stencil. The various shapes and lines have specific meanings and rules behind them, and both the shapes and the rules were developed for the purposes of process modeling, independent of an underlying execution language for implementation. (BPMN does assume the runtime engine can support events that interrupt tasks and subprocesses, a natural feature of SOA-era engines missing in some traditional workflow engines.)

Specifically, process modeling is inherently a business function that does not require understanding of the technical detail of the implementation. In order to be universally understood by business process analysts, BPMN has only three basic shapes – activity (a step in the process that performs work), gateway (routing control logic), and event (a signal that something has “happened”). That’s it, just three. But with a few standard subtypes of these three basic shapes, BPMN is also precise enough to support detailed simulation analysis, and in tools like Appian, Lombardi, Savvion, or Intalio, the front end of executable design as well.

Much of the energy behind adoption of BPMN as a standard is in fact uptake by the BPM suite vendors as a design front end. Its advantage is that it supports a new rapid iterative implementation style based on continuous business/IT collaboration, instead of the alternative “handoff” style in which changes made in the executable design environment can get out of sync with the model (the notorious “round-tripping” problem). But we should not lose sight of the fact that BPMN is first and foremost a modeling notation, intended for use by business.

What’s always been missing in BPMN has been portability, the simple idea that a valid model drawn in tool A can be imported into tool B with the assurance that it will still “work”. To me that means two things we don’t yet have: 1) a specified subset of the BPMN shapes (including subtypes and their attributes) that must be supported; and 2) a unique and unambiguous mapping from the diagram to XML. With BPEL we have neither of these problems. You need to support all of it to be compliant, and BPEL itself defines the XML. In other words, BPEL is a “language.”  (The penalty BPEL pays for this is that the language does not include everything you need, but that’s another story.)

So what would BPMN as a language look like? The mapping between the graphics and the XML would be simple and unambiguous. The metamodel, or interrelationship of these concepts, is already defined in the BPMN 1.0 spec narrative, which is essentially unchanged in three years. The detailed semantics of that metamodel, while perhaps not something you can plug into a developer tool like Eclipse, is precise enough to serve BPMN’s primary purpose, which is process modeling by business. More precise semantics required for detailed process execution or model-driven architecture, could be layered on afterward in the design environment.

The benefits of treating BPMN as a language would be twofold. The first benefit is guaranteed portability of models. This is so absolutely fundamental it’s amazing that BPMN has gotten as far as it has without it. The second benefit is reinforcing to process modelers that there are precise semantics and rules behind the BPMN shapes. People naturally accept there is some rigorous structure behind a language, but somehow think that graphics can mean whatever you want them to mean. The language would not impose constraints such as BPEL’s block-oriented structures on the process modeler – you can still freely connect anything to anything (more or less) – but users might be more inclined to learn the rules, and tools would provide validators that make it easier to follow them.

My problem with both BPDM and the Intalio efforts to date are that they are not designed for process modelers, but for developers using Eclipse. Both complicate the modeling “language” with artifacts of Eclipse’s inherently non-business-friendly model-driven architecture, called EMF. In other words, the XML schema for BPMN is not designed to be a simple tool-independent reflection of the “language”, but instead something that an Eclipse-based BPMN tool can leverage, along with EMF, to generate executable code. That’s a different purpose entirely.

How does this “pollute” the schema?  Each XML element generates 15 Java classes using Eclipse MDA, and if you had a “sensible” schema the implementation code would be too unwieldy. In other words, the Java tail is wagging the BPMN dog. I suspect the BPDM serialization will be even worse from a business modeling perspective.  So far the schema they have published is not even valid per the XML schema language, and contains no root elements, something needed by any XML tool (but maybe not by Eclipse).

XPDL 2.0, on the other hand, is based on “real” XML, but it does not use the language of BPMN at all. Recall that XPDL originally was intended as a generic interchange format between 100 proprietary workflow tools. To support BPMN, XPDL 2.0 essentially enlarged it to 101. In other words, XPDL guarantees there is a place to stuff any BPMN shape, line, or attribute, but the schema does not reflect the BPMN metamodel, terminology, or semantics. This still might be the best option, but with so many different places to stuff the info, it’s not clear that the BPMN-to-XPDL mapping is unambiguous, i.e. portability without a side agreement between tool vendors may not be assured.

A commonly accepted portability standard for BPMN is still just out of reach.  To be fair, both BPDM and the Intalio efforts are still work in progress, and WfMC could always tweak XPDL if they sense an opportunity. I think if we began to think about BPMN as a language instead of just a drawing format, it might show a clearer path to the desired end result.

Similar Resources

Featured Certificate: BPM Specialist

Everyone starts here.

You're looking for a way to improve your process improvement skills, but you're not sure where to start.

Earning your Business Process Management Specialist (BPMS) Certificate will give you the competitive advantage you need in today's world. Our courses help you deliver faster and makes projects easier.

Your skills will include building hierarchical process models, using tools to analyze and assess process performance, defining critical process metrics, using best practice principles to redesign processes, developing process improvement project plans, building a center of excellence, and establishing process governance.

The BPMS Certificate is the perfect way to show employers that you are serious about business process management. With in-depth knowledge of process improvement and management, you'll be able to take your business career to the next level.

Learn more about the BPM Specialist Certificate





  • Business Process Management Specialist
  • Earning your Business Process Management Specialist (BPMS) Certificate will provide you with a distinct competitive advantage in today’s rapidly evolving business landscape. With in-depth knowledge of process improvement and management, you’ll be able to take your business career to the next level.
  • BPM Professional Certificate
    Business Process Management Professional
  • Earning your Business Process Management Professional (BPMP) Certificate will elevate your expertise and professional standing in the field of business process management. Our BPMP Certificate is a tangible symbol of your achievement, demonstrating your in-depth knowledge of process improvement and management.


BPM Certification

  • Make the most of your hard-earned skills. Earn the respect of your peers and superiors with Business Process Management Certification from the industry's top BPM educational organization.




  • Operational Excellence Specialist
  • Earning your Operational Excellence Specialist Certificate will provide you with a distinct advantage in driving organizational excellence and achieving sustainable improvements in performance.


OpEx Professional Certificate

  • Operational Excellence Professional
  • Earn your Operational Excellence Professional Certificate and gain a competitive edge in driving organizational excellence and achieving sustainable improvements in performance.



  • Agile BPM Specialist
  • Earn your Agile BPM Specialist Certificate and gain a competitive edge in driving business process management (BPM) with agile methodologies. You’ll gain a strong understanding of how to apply agile principles and concepts to business process management initiatives.  

Business Architecture



  • Business Architecture Specialist
  • The Business Architecture Specialist (BAIS) Certificate is proof that you’ve begun your business architecture journey by committing to the industry’s most meaningful and credible business architecture training program.

  • Business Architecture Professional
  • When you earn your Business Architecture Professional (BAIP) Certificate, you will be able to design and implement a governance structure for your organization, develop and optimize business processes, and manage business information effectively.

BA CertificationCertification

  • Make the most of your hard-earned skills. Earn the respect of your peers and superiors with Business Architecture Certification from the industry's top BPM educational organization.




  • Digital Transformation Specialist
  • Earning your Digital Transformation Specialist Certificate will provide you with a distinct advantage in today’s rapidly evolving business landscape. 


  • Digital Transformation Professional
  • The Digital Transformation Professional Certificate is the first program in the industry to cover all the key pillars of Digital Transformation holistically with practical recommendations and exercises.



  • Agile Business Analysis Specialist
  • Earning your Agile Business Analysis Specialist Certificate will provide you with a distinct advantage in the world of agile software development.


  • DAS Certificate
  • Decision Automation Specialist
  • Earning your Decision Automation Certificate will empower you to excel in the dynamic field of automated decision-making, where data-driven insights are pivotal to driving business innovation and efficiency.