introduction to omg's new standard dmn 1.0

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)?

Alcedo Coenen

Enterprise Architect

Be Informed

a.coenen@beinformed.com