Quick guide

DMN Glossary and Terminology



The production of a single result from multiple hits on a decision table. There are four aggregation operators on the Collect hit policy: + (sum), < (min), > (max), # (count). If no operator is specified, the results of the Collect hit policy are returned without being aggregated.


A hit policy for single hit decision tables with overlapping decision rules: under this policy any match may be used.

Authority Requirement

It happens when one element of a Decision Requirements Graph is depending on another element providing guidance to it or acting as its knowledge origin.


Business Knowledge Model

Some decision logic (for example a decision table) compressed as a reusable function, which may be referred to by decisions or by other business knowledge models



In a decision table, it specifies a subject, defined by an input expression or an output domain, and the restricted set of the subdomains of the subject’s domain which are relevant for the piece of decision logic detailed in the decision table.


Under the "Collect" hit policy all matches in a multiple hit decision table will be returned as a list in arbitrary order. See Aggregation to add an operator and specify a function to apply to the outputs.



A decision happens when an output value is derived from a number of input values, using decision logic determining how the output is defined from the inputs.

Decision logic

The logic used to make decisions, defined in DMN as the value expressions of decisions and business knowledge models. It is represented visually as boxed expressions.

Decision Logic Level

The detailed level of modeling in DMN. It is made of the value expressions connected with decisions and business knowledge models.

Decision Model

A formal model of an area of decision-making. In DMN it is represented as decision requirements and decision logic.

Decision Point

A point in a business process at which decision making happens, modeled in BPMN 2.0 as a business rule task.

Decision Requirements Diagram

A diagram presenting a global or partial view of a Decision Requirements Graph.

Decision Requirements Graph

A set of DRG elements (decisions, business knowledge models and input data) connected by requirements so they can form a graph.

Decision Requirements Level

The more abstract level of modeling in DMN, made of a DRG displayed in one or more DRDs.

Decision rule

In a decision table, a decision rule couples a set of conclusions or results (output entries) with a set of conditions (input entries).

Decision Table

A tabular representation of a set of related input and output expressions, which is ordered into decision rules suggesting which output entry applies to a distinct set of input entries.


A container for all elements of a DMN decision model. The interchange of DMN files always has to go through one or more Definitions.

DMN Element

Any element of a DMN decision model: a DRG Element, Business Context Element, Expression, Definitions, Element Collection, Information Item or Item Definition.


See Decision Requirements Diagram.


See Decision Requirements Graph.

DRG Element

Any component of a Decision Requirements Graph: a decision, business knowledge model, input data or knowledge source.



A literal expression, decision table, invocation, list, context, function definition, or relation used to characterize part of the decision logic for a decision model in DMN. When interpreted it must give a single value as a result.



A hit policy for single hit decision tables with overlapping decision rules: under this policy the first match is used, following the order of the decision rules.



In a decision table, the successful pairing of all input expressions of a decision rule. In this way, the conclusion becomes eligible for inclusion in the results.

Hit policy

A hit policy shows how overlapping decision rules have to be interpreted. A single hit table shows as a result the output of one rule only; a multiple hit table may show the output of multiple rules or an aggregation of the outputs.


This is the orientation for decision tables where decision rules are presented as rows and clauses are represented by columns.


Information requirement

When a decision is dependent on an input data element or on another decision, so it can give a variable to be used in its decision logic.

Input Data

An input data describes the information utilized as an input by one or more decisions, whose value is defined outside of the decision model.

Input entry

An expression which describes a condition cell in a decision table (for example, the intersection of a decision rule and an input clause).

Input Expression

An expression describing the item that needs to be compared with the input entries of an input clause in a decision table.

Input Value

An expression which describes a defined range of expected values for an input clause in a decision table.

Item Definition

An item definition is adopted to model the structure and the range of values of input data and the outcome of decisions.


Knowledge Requirement

We have a Knowledge Requirement when a decision or business knowledge model is based on a business knowledge model which must be invoked in the evaluation of its decision logic.

Knowledge Source

An authority defined for decisions or business knowledge models ( for example, domain experts responsible for describing or maintaining them), or source documents from which business knowledge models come from or sets of test cases with which the decisions must be consistent.


Multiple Hit

A decision table type which may return output entries from multiple decision rules.


Organizational unit

A business context element showing the unit of an organization making or owning a decision.

Output entry

An expression which outlines a conclusion cell in a decision table (for example, the intersection of a decision rule and an output clause).

Output order

A hit policy for multiple hit decision tables with overlapping decision rules: under this policy all matches are going to be returned as a list in decreasing priority order. Output priorities are pointed out in an ordered list of values.

Output value

An expression defining a specific range of domain values for an output clause in a decision table.



A hit policy for single hit decision tables with overlapping decision rules: under this policy the match with the highest output priority is used/selected.



It happens when a DRG element depends on another one. It could be either an information requirement, or knowledge requirement or authority requirement.

Requirement Subgraph

The directed graph that comes out from the transitive closure of the requirements of a DRG element. For example this could be the sub-graph of the DRG showing all the decision-making required by a particular element.

Rule Order

A hit policy for multiple hit decision tables with overlapping decision rules: under this policy all matches are going to be returned as a list in the order of definition of the decision rules.


Single Hit

A type of decision table which may selects the output entry of only a single decision rule.



A hit policy for single hit decision tables where no overlap is allowed and all decision rules are exclusive. Only a single rule must be matched.



A variable represents a value that is input to a decision, in the description of its decision logic, or a value passed as a parameter to a function.



A DRG element or requirement utilized to show that it adapts to constraints on referential integrity, acyclicity and so on.

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