What is Decision Model and Notation

Decision Model and Notation (DMN) is a standard published and managed by the Object Management Group (OMG). It provides a standard approach for describing, modeling and implementing repeatable decisions within an organization or an initiative. It is also intended to facilitate the sharing and interchange of decision models between organizations.

The modeling notation is comprised of a visual grammar that allows decisions and business rules to be documented in a way that makes them readable by both business and technical audiences thus ensuring that decisions and rules are not misinterpreted. The resulting Decision Model also provides a definition of how to evaluate the logic of decisions defined in Decision Tables using the Friendly Enough Expression Language (FEEL).

The DMN defines two level of the language which neatly align with organizational roles as follows:

Requirements Level

Aligns with the business people who devise, analyze and define the decision rules. This provides a mechanism for the people who own the business to model them without the need for technical knowledge of how they are implemented.

Logic Level

Aligns with implementation teams who augment the definitions to include decision logic in the form of decision tables that can be maintained by the business staff or expression logic managed by technical staff.