The benefits of using BPMN and DMN together

Tom Debevoise and I gave a webinar this week on 4 key benefits of using the Business Process Model and Notation (BPMN) and the Decision Model and Notation (DMN) standards. We highlighted the power of these two standards in combination, specifically in terms of:

• Streamlined processes
  A combination of process modeling and decision modeling produces simpler business processes by eliminating unnecessary gateways and scripting activities. Instead of capturing decision logic in the process model, decision modeling captures this logic precisely in a separate but linked model.
• Focused discovery
  By focusing on decisions and processes independently the discovery processes is more focused. Different stakeholders are involved in the process and the decisions within it so separate models often work better. Because the pair of models are each simpler than a single combined model, the discovery and modeling activities are easier to manage and complete successfully. Decision models link the tasks in a process to the business rules that will be required as well as to the organizations and business metrics that matter. All this makes the discovery process more effective.
• Improved visibility and flexibility
  DMN structures and manages the business rules that a process requires, gathering them into a coherent model at each decision point in the process. This makes it easier to find the right rules to change and allows the rules (decision) to be changed independently of the process improving flexibility. Because the decision models are linked to business metrics too, organizations get visibility into how their rules impact their business performance through the model.
• Greater analytic agility
  DMN provides a model of the decision making in a process and this allows the impact of analytic models to be clearly expressed, allowing increasingly advanced analytics to be integrated into a process.

In the webinar we got some great questions that I thought I would blog about:

• Are there certain kinds of decision that can and can’t be modeled in DMN? E.g. routine decisions, like “What discount should I offer?”, vs. strategic decisions like “Should we open an office in China”?
  Absolutely. DMN is designed to model repeatable decisions- decisions you make more than once. These decisions are generally operational or tactical in nature with most being operational. Strategic decisions generally don’t lend themselves to modeling because there is no prior experience to analyze to see what the model should be. Like process models, decision models are focused on repeatable activities.
• Is the decision table containing the actual rules standardized too
  DMN standardizes both the decision requirements model – a diagram allowing the decomposition and modeling of decisions – and decision tables. Decision tables can be defined for any decision in the model to completely specify the logic for that decision. The standard allows for other approaches to specifying decision logic such as analytic models or decision trees but only standardizes decision tables.
• Isn’t the decision table a bit too simple compared with analytics techniques (even a decision tree) ?
  Decision tables are great for engaging business users and business analysts because they are easy to read, write and validate. That said they are not perfect for every use and so future versions of DMN are expected to add decision trees and other representations. In addition more complex decision-making artifacts like predictive analytic models can be used to represent decisions in DMN models also. The Enterprise Edition of our decision modeling tool DecisionsFirst Modeler is specifically designed to allow models to be implemented in a variety of technologies not just decision tables.
• Which parts of DMN are executable?
  Like BPMN, DMN allows a complete executable model to be defined. This involves specifying the decision tables and input data information structures as well as the necessary constructs/logic for passing data around. In theory a model that can be represented entirely by decision tables could be 100% executable.
• Would you say that hierarchical decisions are similar to declarative rules?
  I think a hierarchical decision model is very compatible with declarative business rules and that’s one of the strengths of DMN. While you can design decisions for implementation in almost anything, implementing them in a Business Rules Management System is a very straightforward exercise.
• DMN models appear to be developed primarily for the IT’s ability to understand the decision. It is not overly business friendly. What notation would you recommend for Business people to verify and validate their knowledge in their own language? Do you feel like the DMN model is the best way to do this? or is there another view that better fits the businesses vocabulary and ability to confirm knowledge?
  Our experience with decision models is that business people and business analysts find the models easy to read, easy to develop and very powerful at expressing their knowledge. While IT appreciate them too, the power of decision models to allow business owners to clearly express their requirements is really impressive. See this decision modeling case study for instance.

We also did some quick polls on process modeling and decision modeling. As you would expect, when it comes to process modeling almost everyone is using BPMN. Nearly 70% of those taking the poll were doing process modeling and using BPMN. Only about 20% were using some other approach with almost no-one not doing process modeling at all. This reflects the well established nature of process modeling and the dominance of BPMN in this space.

Decision Modeling is newer and less well established. A similar poll showed only 10% already using the new Decision Model and Notation standard (DMN) with over 30% not using any decision modeling at all. The remainder are using decision modeling – either a proprietary approach or decision tables I suspect. With DMN nearing official publication, a number of tools supporting DMN (including our own DecisionsFirst Modeler) and at least one book (Tom and my MicroGuide to Process and Decision Modeling in BPMN/DMN) I expect adoption to rise steadily in 2015.

 

 

You can watch the recorded webinar here and the slides are below. Don’t forget you can sign up for DecisionsFirst Modeler, our DMN modeling tool, here and you can buy Tom and my new book The MicroGuide to Process and Decision Modeling in BPMN/DMN: Building More Effective Processes by Integrating Process Modeling with Decision Modeling.