DMN Decision Requirements Diagram

Red Hat Decision Manager 7: Part 3-2 A DMN Demo

In the last video, I gave a short introduction to Decision Model and Notation or DMN. It contains sufficient info to understand this demo.

This demo includes:

  • Enabling the Decision Central DMN Editor
  • Using the Decision Central DMN Editor
  • Writing a Test Scenario
  • Deploying a DMN Project on the Execution Server
  • Interacting with the deployed DMN Model using REST API

I am going to show you how to create a DMN Decision model from start to finish.

The Decision Requirement Diagram is shown at the top of the page (above).

Notice that I put the decision table in the Business Knowledge Model (BKM).¬†And the use of FEEL (Friendly Enough Expression Language) in the “age” column.

DMN Business Knowledge Model
DMN Business Knowledge Model

One can also put the decision table directly in the Decision Node itself. The difference is that by putting the decision table in the BKM, it can be reused in another Decision node. There is no advantage in doing it this way in such a simple demo but imagine the reuse value in a large decision model.

The diagram below shows how the decision node invokes the decision table in the BKM. It maps the data to the variable (Age) used in the decision table. This is like a subroutine call in a programming language.

DMN Decision Node
DMN Decision Node

Here is the video: