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A short introduction to the new standard for Decision Model and Notation (DMN) by OMG. Concluded with some personal remarks and questions. Based on the beta publication, as announced by James Taylor in his blog (http://jtonedm.com/2013/09/26/decision-model-and-notation-an-introduction-to-the-beta-specification/)
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Alcedo Coenen
Oct 2013
Decision Model & Notation
(DMN 1.0) – a new OMG Standard
This is an introduction to the recently defined standard for
Decision Model & Notation (DMN), published by OMG …
… closed with some personal comments and questions.
See also James Taylors blog with a good overview of the
standard, and the link to the report itself.
Proposal for:
Decision Model and Notation (DMN) Specification
1.0
August 23, 2013
Agenda
• Purpose & Overview
• Concepts
• Decision Requirements
• Notation
• Use
• Decision Logic
• Language
• Table
• Comments
Purpose of DMN
• Model decisions
• Depict in diagrams
• Defined by business
analysts
• (optionally) automated
Overview (Contents of the Standard document)
1. Scope
2. Conformance
3. Normative References
4. Introduction to DMN
5. Decision Requirements (DRG and DRD)
6. Relating Decision Logic to Decision Requirements
7. Decision Table
8. Simple Expression Language (S-FEEL)
9. Expression Language (FEEL)
10. DMN Example
11. Exchange Formats
Annexes:
A. Relation to BPMN
B. Decision Services
C. Responses to RFP Requirements
D. Glossary
Agenda
• Purpose & Overview
• Concepts
• Decision Requirements
• Notation
• Use
• Decision Logic
• Language
• Table
• Comments
Conceptual context
Main concepts
Decision Logic
Decision Requirements
Business Process
More
deta
ils
2 levels in scope
Main concepts
Decision Logic
Decision Requirements
Business Process
More
deta
ils
Main concepts – Decision Requirements Level
• Business concepts only
• Business decisions
• Areas of business knowledge
• Sources of business knowlegde
Decision Requirements
Main concepts
• Greater detail
• Business rules
• Calculations
• Automated
• Display
Decision Logic
From Requirement to Logic
Decision Logic
Decision Requirements
From Requirement to Logic
“This will allow the import of many existing
decision logic modeling standards (e.g. for
business rules and analytic models) into DMN”
Supported by DMN
SBVR
Agenda
• Purpose & Overview
• Concepts
• Decision Requirements
• Notation
• Use
• Decision Logic
• Language
• Table
• Comments
Notation
• DRG
• Decision Requirements Graph
• Self-contained, complete for 1 Decision
• DRD
• Decision Requirements Diagram
• = View on DRG
• Incomplete, showing specific aspects or
perspectives
DRG/DRD elements
Decision
BusinessKnowledge
Input data
Knowledge Source
= the act of determining an output from
a number or input values
= a function encapsulating business
knowledge
= information used as input
= authority for business knowledge or
decision
DRG/DRD relationships
= used as input
= Information Requirement
= invokes
= Knowledge Requirement
= depends on
= Authority Requirements
Allowed relationships
Decision 1
BusinessKnowledge
Knowledge Source
Decision 2 DecisionInput data
Knowledge SourceDecision
Decision
BusinessKnowledge
2
BusinessKnowledge
1
Knowledge Source Decision
BusinessKnowledge
Knowledge Source 2
Knowledge Source
Knowledge Source 1
Input data
Decision 1 is used as input for decision 2
Decision depends on Knowledge Source
Business Knowledge invokes a Decision
Business Knowledge 1 invokes Business Knowledge 2
Input data is used as input for decision
Input data depends on Knowledge Source
Knowledge Source depends on Decision
Knowledge Source depends on Business
Knowledge
Knowledge Source 1 depends on Knowledge
Source 2
Example DRD
Agenda
• Purpose & Overview
• Concepts
• Decision Requirements
• Notation
• Use
• Decision Logic
• Language
• Table
• Comments
Use of DMN
1. Modeling human decision-making
2. Modeling requirements for
automated decision-making
3. Implementing automated
decision-making
modelrequirements
Decision-
making
Decision-
making
implementati
on
12
3
Agenda
• Purpose & Overview
• Concepts
• Decision Requirements
• Notation
• Use
• Decision Logic
• Language
• Table
• Comments
Connecting Requirements to Logic
Decision Logic
Decision Requirements
The decision logic level of a decision model in DMN consists in one or more value expressions.
Languages for Value Expressions
Possible value expression forms:
• Literal expression
• Decision table
• Invocation of a Business Knowledge Model (re-usable function)
FEEL = Friendly Enough Expression Language
Agenda
• Purpose & Overview
• Concepts
• Decision Requirements
• Notation
• Use
• Decision Logic
• Language
• Table
• Comments
Decision Table cf DMN 1.0 - principles
IF input expression 1 matches x AND
input expression 2 matches y THEN a
result (a "hit") is z.
• Name
• Set of inputs
• Set of outputs
• Rules connecting inputs with outputs
S-FEEL = subset of FEEL
Decision Table cf DMN 1.0 - styles
Rule = row
Rule = column
Rule = crosstab
Agenda
• Purpose & Overview
• Concepts
• Decision Requirements
• Notation
• Use
• Decision Logic
• Language
• Table
• Comments
Semantic analysis (simplified)
Decision
Authority
Output value
Input value(s) Decision logic
Business
Knowledge Models
Business
know-how
Business RuleAnalytical
model
hasdetermines
requires uses
includes
encapsulates
kind of kind of
has
Value
expression
defined by
defined by
Question marks
• Hierarchy from business
process to business logic
• => what about knowledge
about the process itself?
• Distinction DRG vs DRD
• Why is the DRG not used in
the Example (Ch 10)?
• Is it more than a difference
in scope?
• Decision vs Business
Knowledge
• What is the difference?
• What are they different
from functions (transforming
input into output)?
• FEEL
• Why a separate language?
• Why no FEEL in the Example
(Ch 10)?
