# Introducing Decision Modeling Notation (DMN)

Objectives

After completing this lesson, you will be able to:

• Explain Decision Modeling Notation (DMN)

Did you know that without landmarks to guide them, humans tend to walk in circles?

This inadvertent outcome is because people naturally lean - ever so slightly - to one side when they walk. Forced to depend on their own sense of direction, these minute deviations in trajectory prevent them reaching their final destination.

Logic in ad hoc decision making is similar. Although the degree and direction of this ‘lean’ is unique to individuals, the impact of small, seemingly inconsequential decisions made without transparent logic to guide business users as they carry out their day-to-day tasks, leads to variation in strategic outcomes.

Business Decision Management (BDM) is designed to enable operational decisions to be managed in a standardized, consistent, and transparent way. BDM acts as your business’ compass as you navigate value creation, calibrating operational decisions for consistency.

Decision diagrams are nodes within a business process, orchestrating the process pathway taken at important points, based on inputs. Decision diagrams have two levels. The first is the decision requirements diagrams, the second contains decision logic.

## Business Process with DMN Extension

Operational decisions affect processes in multiple ways. Decisions can direct the next step in the process, indicate who is responsible for the activity, or give the required information to complete the decision.

Let's take a look at an example process model.

In this process model example, we see the first activity is the decision Determine how to eat dinner. The outcome of the decision determines the next activity to take at the gateway.

## Decision Requirements

DMN models include 2 levels of information:

• Decision requirement diagrams (that is DMN diagrams)
• Decision logic

DMN diagrams provide a high-level view of any dependencies with other decisions, policies, and input data.

In the above example, the decision Determine how to eat dinner, depends on the inputs. Motivated to go out? Motivated to cook? as well as the sub-decision, Determine available budget.

## Decision Logic

Decision logic specifies the details of a decision so that it can be easily and unambiguously understood. The decision logic is contained in a decision table, which can be shown by clicking on the decision.

## Decision Models vs Process Models

Each model type has its own purpose and complements the other. Both models can exist independently.

### Process Example

Take a look at the process example below.