Decision Model and Notation (DMN)

  Decision model and Notation (DMN) is a model used to describe how decisions are made within an organization. The model is adopted by the Object Management Group (OMG) as one of their standards.

The model consist of two levels, the Decisions requirements level and the Decision logic level.

Decision requirements level

The decision requirements level is a high level structure of decisions, sub-decisions and inputs. The requirements level also has references to business knowledge and knowledge sources.
A decision requirements graph is used to create a graphical high level model on how a decision is made. An example is shown below.

DRG for the calculation of the riskscore for an insurance claim

The model should be read as: The decision Riskscore is calculated:

• according to the logic in the knowledge model RiskScoreCalculation
• with the results from the sub decisions RiskScore Bonus and RiskScore Penalties as input
• using further input data from CustomerDossier to calculate the RiskScore Bonus
• with the source ClaimPolicy containing the policy description on how to calculate the risk score.

The model consist of four different type of shapes and the connections between them. These different shapes are:

Decision logic level

The decision logic level describes how different inputs will lead to a single answer for a question. The decision logic level contains logic elements, like decision tables and business rule. These logic elements make it possible to derive a result for a decision. These logic elements are connected to the requirements level using the business knowledge model. The official description of DMN contains a specification of their view on decision tables and an expression language.

The DMN specification allows implementations to use other types of logic elements than the ones proposed in the specification. Since Blueriq already has its own models to create logic, we will be using these for our models. For that reason the logic elements described in the specification will not be described further in this document.

Further information can be found in the specifications here: http://www.omg.org/spec/DMN/1.0/Beta1/