ISO/TS 20022-5:2004

TECHNICAL ISO/TS
SPECIFICATION 20022-5
First edition
2004-12-15
Financial services — UNIversal Financial
Industry message scheme —
Part 5:
ISO 20022 reverse engineering
Services financiers — Schéma universel de messages pour l'industrie
financière —
Partie 5: Ingénierie inverse ISO 20022

Reference number
©
ISO 2004
PDF disclaimer
This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but
shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In
downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat
accepts no liability in this area.
Adobe is a trademark of Adobe Systems Incorporated.
Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation
parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In
the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below.

©  ISO 2004
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,
electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or
ISO's member body in the country of the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Published in Switzerland
ii © ISO 2004 – All rights reserved

(Blank page)
Contents
Foreword
1 Introduction. 5
2 Terms and definitions. 6
3 Activities and deliverables. 7
3.1 Gap analysis.7
3.2 Development of ISO 20022 compliant Business Transactions and Message
Sets. 8
3.3 ISO 20022 Registration. 8
3.4 Preparation of migration.9
4 Workflow. 9
4.1 Gap analysis.9
4.1.1 Industry Message Set documentation collection . 10
4.1.2 Business Area gap analysis. 12
4.1.3 Business Process gap analysis . 13
4.1.4 Business Transaction gap analysis. 15
4.1.5 Message Definition gap analysis . 18
4.1.6 Business Roles gap analysis . 21
4.2 Development of ISO 20022 compliant Business Transactions and Message
Sets. 23
4.2.1 A new Business Area. 24
4.2.2 A modified Business Area . 25
4.2.3 A new Business Process . 25
4.2.4 A modified Business Process. 26
4.2.5 A requirements use case . 26
4.2.6 A new Business Transaction. 27
4.2.7 A modified Business Transaction. 27
4.2.8 A new Message. 28
4.2.9 A modified Message.28
4.2.10 A new or modified Business Role . 29
4.3 ISO 20022 registration. 29
4.4 Preparation of migration.30
4.4.1 Convergence documentation.31
4.4.2 Coexistence documentation.35
4.4.3 Migration planning.35
Annex A: Convergence documentation . 37
A.1 Data Type convergence tables . 37
A.2 Element convergence tables.38
A.3 Message convergence tables.38
A.4 Message Item convergence tables. 39
A.5 Some simple examples. 40
A.5.1 Data Type convergence tables . 40
A.5.2 Element convergence tables.41
A.5.3 Message convergence tables.42

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national
standards bodies (ISO member bodies). The work of preparing International Standards is normally
carried out through ISO technical committees. Each member body interested in a subject for which a
technical committee has been established has the right to be represented on that committee.
International organizations, governmental and non-governmental, in liaison with ISO, also take part
in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all
matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives,
Part 2.
The main task of technical committees is to prepare International Standards. Draft International
Standards adopted by the technical committees are circulated to the member bodies for voting.
Publication as an International Standard requires approval by at least 75 % of the member bodies
casting a vote.
In other circumstances, particularly when there is an urgent market requirement for such documents,
a technical committee may decide to publish other types of normative document:
— an ISO Publicly Available Specification (ISO/PAS) represents an agreement between technical
experts in an ISO working group and is accepted for publication if it is approved by more than
50 % of the members of the parent committee casting a vote;
— an ISO Technical Specification (ISO/TS) represents an agreement between the members of a
technical committee and is accepted for publication if it is approved by 2/3 of the members of
the committee casting a vote.
An ISO/PAS or ISO/TS is reviewed after three years in order to decide whether it will be confirmed
for a further three years, revised to become an International Standard, or withdrawn. If the ISO/PAS
or ISO/TS is confirmed, it is reviewed again after a further three years, at which time it must either
be transformed into an International Standard or be withdrawn.
Attention is drawn to the possibility that some of the elements of this document may be the subject
of patent rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO/TS 20022-5 was prepared by Technical Committee ISO/TC 68 to complement ISO 20022-1,
Overall methodology and format specifications for inputs to and outputs from the ISO 20022
Repository, with the reverse engineering guidelines explaining how to extract relevant information
from existing industry message sets in order to prepare the submission to the ISO 20022
Registration Authority of equivalent ISO 20022 compliant business transactions and message sets.
This Technical Specification should be reviewed and considered for publication as an International
Standard once further experience has been gained in using these guidelines.
ISO 20022 consists of the following parts, under the general title Financial services — UNIversal
Financial Industry message scheme:
 Part 1: Overall methodology and format specifications for inputs to and outputs from the
ISO 20022 Repository
 Part 2: Roles and responsibilities of the registration bodies
 Part 3: ISO 20022 modelling guidelines [Technical Specification]
 Part 4: ISO 20022 XML design rules [Technical Specification]
 Part 5: ISO 20022 reverse engineering [Technical Specification]
1 Introduction
The ISO 20022 Repository will contain all ISO 20022 compliant Business Transactions and
Message Sets, as outlined in ISO 20022-1. The approach that must be followed to add ISO
20022 compliant Business Transactions and Message Sets to the Repository can be
classified as follows:
a) Case 1:
No ISO 20022 compliant Business Transactions and Message Sets exist
No Industry Message Set exists
• Example: Collective Investment Vehicles
• Approach: full development of ISO 20022 compliant Business Transactions and
Message Sets using the ISO/TS 20022-3 Modelling guidelines.
b) Case 2:
No ISO 20022 compliant Business Transactions and Message Sets exist
One or more Industry Message Sets exist
• Example: Securities Pre-Trade (FIX Message Set exists)
• Approach: conversion of the Industry Message Set(s) into ISO 20022 compliant
Business Transactions and Message Sets, using ISO/TS 20022-5 Reverse
engineering guidelines.
c) Case 3:
ISO 20022 compliant Business Transactions and Message Sets exist
One or more existing Industry Message Sets exist as well
• Example: Securities Post-Trade (FIX, Omgeo Message Sets exist)
• Approach: comparison of the existing Industry Message Set(s) with the ISO 20022
compliant Business Transactions and Message Sets and extension of the ISO 20022
compliant Business Transactions and Message Sets as necessary, using ISO/TS
20022-5 Reverse engineering guidelines.
This document describes the activities of “ISO 20022 reverse engineering” from the point
of view of the user who wants to verify that the business functionality, covered by his own
Industry Message Set, is covered by ISO 20022 compliant Business Transactions and
Message Sets. The document is not an attempt to define a “methodology” for reverse
engineering.
It describes the following set of required activities:
• Extract relevant information from existing Industry Message Sets and compare it to the
related information in the ISO 20022 Repository

The document is based on preliminary reverse engineering experiences in the framework of “electronic
Business Oriented Methodology” (eBOM) and of “SWIFTStandards Modelling methodology”. It has been
enriched on the basis of the work conducted in domain groups of the ISO/TC68/SC4/WG10 reverse
engineering project team and on the results of the ISO/TC68/SC4/WG10 Proof of Concept.
• Use the results of this comparison for the development of ISO 20022 compliant
Business Transactions and Message Sets
• Submit the resulting update requests to the Registration Authority
• Prepare the migration to the ISO 20022 compliant Business Transactions and Message
Sets.
The main objectives of the “ISO 20022 reverse engineering” are as follows:
• Capture the industry knowledge covered by existing Industry Message Sets
• Build upon former standardization efforts in the industry when building ISO 20022
compliant Business Transactions and Message Sets
• Ensure that the resulting ISO 20022 compliant Business Transactions and Message Sets
fully cover the business scope of existing Industry Message Sets
• Maximise interoperability between existing Industry Message Sets and ISO 20022
compliant Business Transactions and Message Sets
• Support the migration from existing Industry Message Sets to ISO 20022 compliant
Business Transactions and Message Sets.
The document is structured as follows:
ƒ Chapter 2 contains some specific terms that are used in this document.
ƒ Chapter 3 describes the major activities that will be conducted during reverse
engineering and also describes at a high level the resulting deliverables.
ƒ Chapter 4 gives a detailed workflow, explaining all activities, inputs and outputs.
ƒ Appendix A contains a detailed description of the Convergence Documentation.
2 Terms and definitions
This document uses the terms and definitions as explained in ISO 20022-1: Overall
methodology and format specifications for inputs to and outputs from the ISO 20022
Repository.
Additionally, particular attention should be given to following terms and definitions that are
used in this document:
Industry Message
A Message that offers a particular Message Functionality (possibly multi-functional) and
whose Message Definition is part of an Industry Message Set.
ISO 20022 Message
A Message that offers a particular Message Functionality and whose Message Definition is
registered in the Business Process Catalogue of the new ISO 20022 Repository.

Note that it is not the intention of reverse engineering to systematically create ISO 20022 compliant versions
of all existing Industry Message Sets. Update requests shall always be based on a valid business justification.
Message Item
An element or field used at a particular place in a Message. This exact place is typically
described by the Message Path.
Message Path
The exact position in a particular Message Definition. This position is uniquely identified
by the full hierarchy (i.e. “path”) from the message level (i.e. the highest level) down to the
element level (i.e. the lowest level).
All these terms are capitalised when used throughout this document.
3 Activities and deliverables
There are four main activities in the “ISO 20022 reverse engineering”:
• Gap analysis
• Development of ISO 20022 compliant Business Transactions and Message Sets
• ISO 20022 registration
• Preparation of migration.
The major objectives and deliverables related to these activities are described in this
chapter.
3.1 Gap analysis
Objectives:
ƒ Determine the Business Area of the Industry Message Set and identify the
corresponding Business Area, Business Processes, activities and supporting Business
Transactions in the ISO 20022 Business Process Catalogue.
ƒ Compare Business Roles in ISO 20022 Business Processes and Business Transactions
to the parties that use the Industry Messages or that are identified in the Industry
Messages.
ƒ Verify whether existing ISO 20022 Messages offer the complete Message Functionality
that is offered by the Industry Messages.
ƒ Evaluate whether the business content of the relevant ISO 20022 Messages cover the
business content of the individual Industry Messages.
ƒ Compare the meaning and the data typing of the used Message Components and/or
Business Components to the individual Industry Message Items.
Deliverables:
ƒ Documentation of the coverage, the differences and the gaps between the Industry
Message Set and the ISO 20022 compliant Business Transactions and Message Sets.
This documentation concerns following repository items:
ƒ Business Areas
ƒ Business Processes
ƒ Business Transactions and Message Sets
ƒ Message Definitions (including Message Rules)
ƒ Business Roles
ƒ Business Components (including Business Elements and Rules)
ƒ Message Components (including Message Elements and Rules)
ƒ Data Types
ƒ The documentation of the Industry Message Set for those repository items that were
missing (i.e. the gaps) or for which a difference was identified.
3.2 Development of ISO 20022 compliant Business Transactions
and Message Sets
Objectives:
ƒ Complete the gap analysis with all additional information that is required to define or
complete ISO 20022 compliant Business Transactions and Message Sets.
ƒ Define the required updates and additions to the existing ISO 20022 compliant Business
Transactions and Message Sets.
This step shall only focus on the identified gaps and differences and shall verify whether
there’s a valid business justification to include these gaps and differences in the ISO 20022
repository. It shall also take into account that the goal of reverse engineering is not to
question (except with respect to the business justification), modify or complement the
business functionality that is currently supported in the Industry Message Set.
Deliverables:
ƒ Detailed documentation describing how the existing ISO 20022 compliant Business
Transactions and Message Sets must be updated to incorporate the identified gaps and
differences.
3.3 ISO 20022 Registration
Objectives:
ƒ Prepare the information for the ISO 20022 Registration Authority to request the update
of the ISO 20022 repository with all required additions and modifications.
Deliverables:
ƒ Requests to the ISO 20022 Registration Authority to add or modify Dictionary Items
and/or Catalogue Items.
3.4 Preparation of migration
Objectives:
ƒ Define and document the relationship between the Industry Message Set and ISO 20022
compliant Business Transactions and Message Sets. The required amount of
information will depend on the chosen migration path:
ƒ in case of a “big bang” migration, it will be sufficient to only document the
relationship in a way that supports the convergence towards ISO 20022
ƒ in case of an accepted period of coexistence there will be a need to have “bi-
directional” documentation that not only supports the convergence towards ISO
20022, but also a backwards mapping to the Industry Message Sets.
ƒ Define a plan for the migration to the ISO 20022 compliant Business Transactions and
Message Sets.
Deliverables:
ƒ Convergence Documentation
ƒ Coexistence Documentation (optional)
ƒ Migration plan
4 Workflow
This chapter contains a detailed workflow description of the four main activities in the
“ISO 20022 reverse engineering”.
4.1 Gap analysis
Preliminary remarks:
• The gap analysis requires a lot of expertise and documentation about the Industry
Message Set. In case this documentation is not readily available, there will be a need
to perform a thorough analysis of the Industry Message Set and its use (see first step
below).
• The gap analysis also requires a lot of documentation about the ISO 20022 compliant
Business Transactions and Message Sets. The repository outputs will include this
documentation.
• Gap analysis is crucial for all subsequent steps:
• Identifying the differences and gaps will define the scope of the subsequent
development of ISO 20022 compliant Business Transactions and Message Sets and
ISO 20022 registration.
• Identifying the overlaps will provide the required information for the Convergence
Documentation and the related migration.
The main steps in gap analysis are shown on the following diagram:
Industry Message Set
documentation collection
2 Business Area gap analysis
3 Business Process gap analysis
4 Business Transaction gap analysis
5 Message Definition gap analysis
6 Business Roles gap analysis
These steps, which are described in more detail in the subsequent paragraphs, will be
executed in an iterative and incremental way. In the “reverse engineering case 2” (i.e. no
existing ISO 20022 compliant Business Transactions and Message Sets) only the collection
of the Industry Message Set documentation needs to be done.
4.1.1 Industry Message Set documentation collection
If the Industry Message Set is well documented (i.e. a full description including the
Business Area, the Business Processes and the Business Transactions), this step is limited
to the explicit identification of the documentation set.
In many cases however, the Industry Message Set documentation will focus only on the
Message Definitions and will mainly document the functionality and content of all Industry
Messages. In some cases, even this documentation may be very limited (e.g. restricted to a
description of the physical structure). In these cases, it is mandatory to complete the
Industry Message Set documentation prior to the reverse engineering.
Activities:
The recommended approach to complete the Industry Message Set documentation is
depicted in the following diagram and further explained in the text.
1 Start from Message Definition
2 Describe Message Functionality
3 Describe business meaning of fields
4 Extract Business Roles
5 Identify Business Transactions
6 Identify Business Processes
7 Identify Business Area(s)
1. Start from the description of the Industry Message Definition.
2. Describe, for each Industry Message, the Message Functionality (i.e. the purpose(s) for
which the Industry Message may be used). Note that Industry Messages may be multi-
functional and that each function should be described.
3. Describe for each Industry Message Item the business meaning. Note that the meaning
of the Item may depend on the specific Message Functionality, in case the Industry
Message is multi-functional. In this case, all meanings must be described.
4. Extract from each Industry Message the Business Roles , by identifying the functional
roles of the sender and the receiver of the Industry Message and by identifying the
functional roles of all other parties that appear in the Industry Message content.
5. Analyse the use of the Industry Messages in order to identify the “Business
Transactions” (i.e. the different message flows that occur in the industry) in which the

One of the big challenges of this step is to identify the real business meaning of the fields.
Note that one Industry Message field may contain multiple Business Elements and/or may contain partial
Business Elements (in which case it may have to be combined with other Industry Message fields to obtain
meaningful Business Elements).
Note that a multi-functional Industry Message will also contain fields to specify the used functionality. These
fields won’t have a corresponding Message Element in the ISO 20022 Message. For these fields, document
the Message Functionality they represent.
Note that an Industry Message may contain “technical” fields, which have no business meaning. In some
cases these fields may have a corresponding technical Message Element in the ISO 20022 Message Definition
but they will never have a corresponding Business Element.
The distinction between “Business Actors” and “Business Roles” is that the latter indicate functional roles
(e.g. buyer, seller, etc.) whereas the first indicate real business parties (e.g. bank, corporate, broker/dealer,
etc.). One Business Actor can play various Business Roles in a business process (e.g. a bank can be a buyer, a
seller, an account servicer, etc.) and various Business Actors can often play the same Business Role (a bank, a
corporate or an individual person can act as buyer).
Industry Messages are used and document each of these Business Transactions, ideally
using a Message Flow Diagram and a textual description.
6. Analyse the list of identified Business Transactions in order to identify the Business
Processes that are supported.
7. Identify the Business Area(s) to which the Business Processes belong.
4.1.2 Business Area gap analysis
The goal is to identify the ISO 20022 Business Areas for which the Industry Message Set is
used. Additionally, investigate whether the Industry Message Set is also used for other
Business Areas that are not yet part of the ISO 20022 Repository.
Input:
• List of ISO 20022 Business Areas, including definitions.
• Industry Message Set documentation related to Business Areas.
Activities:
The recommended approach for Business Area gap analysis is depicted in the following
diagram and further explained in the text.
Industry
ISO 20022
Message
Business
Set
Areas:
documentation
• Definition
Compare Business Area(s)
Document coverage, differences
and gaps
Business Area
•
coverage
• differences
• gaps
1 Go through the list of Business Areas that are stored in the ISO 20022 Business Process
Catalogue. Use the definitions of these Business Areas to identify the Business Area(s)
that best cover(s) the Business Area(s) of the Industry Message Set.
2 Following cases can be identified:
ƒ None of the ISO 20022 Business Areas covers the Business Area(s) of the Industry
Message Set.
- Document this additional Business Area, based on the documentation of the
Industry Message Set.
ƒ One or multiple ISO 20022 Business Areas cover precisely the Business Area(s) of
the Industry Message Set.
- Document this coverage.
- Document possible differences that are identified between the definition of the
Business Area in ISO 20022 and in the corresponding Industry Message Set.
ƒ One ISO 20022 Business Area covers more than the Business Area(s) of the
Industry Message Set.
- Document what part of the ISO 20022 Business Area covers the Industry
Message Set.
- Document possible differences that are identified between the definition of the
Business Area in ISO 20022 and in the corresponding Industry Message Set.
ƒ One or multiple ISO 20022 Business Areas cover a part of the Business Area(s) of
the Industry Message Set and the rest of the Industry Message Set is not covered.
- Document each coverage (i.e. which part of which ISO 20022 Business Area
covers which part of the Industry Message Set).
- Document the part of the Industry Message Set that is not covered, based on the
documentation of the Industry Message Set.
- Document possible differences that are identified between the definition of the
Business Area in ISO 20022 and in the corresponding Industry Message Set.
Output:
• List of ISO 20022 Business Areas that cover (parts of) the Business Area(s) of the
Industry Message Set (including, where necessary, a description of which parts of the
Business Area(s) of the Industry Message Set are covered). This list will include
possible differences in definition that have been identified.
• List of additional Business Areas that are not covered by existing ISO 20022 Business
Areas. Each Business Area in this list will contain a definition, based on the Industry
Message Set documentation.
4.1.3 Business Process gap analysis
The goal is to identify the ISO 20022 Business Processes for which the Industry Message
Set is used and to investigate whether the Industry Message Set is also used for other
Business Processes that are not yet part of the ISO 20022 Repository.
Input:
• ISO 20022 Business Process documentation:
– Definition
– ISO 20022 Business Process descriptions, Business Process Diagram and Business
Activity Diagram
• Industry Message Set documentation related to Business Processes.
Activities:
The recommended approach for Business Process gap analysis is depicted in the following
diagram and further explained in the text.
Business Area
Industry
ISO 20022
•coverage
Message
Business
•differences
Set
Processes:
•gaps
documentation
• Definition
• Diagram
Search matching Business Process(es
) in
identified ISO 20022 Business Area(s)
Define additional Business Process(es) in
identified ISO 20022 Business Area(s)
Define Business Process(es) in additional
Business Area(s)
Business Process
• coverage
• differences
• gaps
1 For each ISO 20022 Business Area that has been identified as one that matches a
Business Area of the Industry Message Set:
ƒ Go through the list of ISO 20022 Business Processes that are stored in the Business
Process Catalogue.
ƒ Use the documentation to identify the ISO 20022 Business Processes that are
supported by the Industry Message Set.
ƒ Document this coverage.
ƒ Document possible differences that are identified between the definition of the
Business Process in ISO 20022 and in the corresponding Industry Message Set.
2 For each ISO 20022 Business Area that has been identified as one that matches a
Business Area of the Industry Message Set:
ƒ Identify any Business Processes that are supported by the Industry Message Set and
that don’t exist yet in ISO 20022.
ƒ Document these additional Business Processes based on the documentation of the
Industry Message Set.
3 For each Business Area that has been identified as one that doesn’t exist yet in ISO
20022:
ƒ Document the Business Processes that are supported by the Industry Message Set.
Output:
• List of ISO 20022 Business Processes – with reference to their ISO 20022 Business
Area – that are supported by the Industry Message Set. This list will include possible
differences in definition that have been identified.
• List of additional Business Processes – with reference to the Business Area to which
they belong – that are not part of the ISO 20022 Repository. Each Business Process in
this list will contain the available Industry Message Set documentation.
4.1.4 Business Transaction gap analysis
The goal is to identify ISO 20022 Business Transactions for which the Industry Message
Set can be used. Additionally, investigate whether the Industry Message Set is also used for
other Business Transactions that are not yet part of the ISO 20022 Repository.
Input:
• ISO 20022 Business Transaction documentation:
– Textual definition
– Message Flow Diagram, including message description.
• Industry Message Set documentation related to Business Transactions and Message
Functionality.
Activities:
The recommended approach for Business Transaction gap analysis is depicted in the
following diagram and further explained in the text.
Business Process
Industry
ISO 20022
•coverage
Message
Business
•differences
Transactions: Set
•
gaps
documentation
• Description
• Message Flow
Search matching Business Transaction and
Message Functionality for identified ISO 20022
Business Processes
Identify additional Industry Business
Transaction(s) in identified Business Process(es)
Identify additional Industry Business
)
es
Transaction(s) in other Business Process(
Search matching Message Functionality for
additional Business Transactions
Business Transaction Message Functionality
• coverage •coverage
• differences •differences
• gaps •gaps
1 For each ISO 20022 Business Process that has been identified as one that matches a
Business Process of the Industry Message Set:
ƒ Use the documentation to identify the ISO 20022 Business Transactions that are
supported by the Industry Message Set.
ƒ Document this coverage.
ƒ Document possible differences that are identified between the documentation
(textual definition and Message Flow Diagram) of the Business Transaction in ISO
20022 and in the corresponding Industry Message Set. Identify possible Message
Functionality that is part of the Business Transaction in the Industry Message Set
and that is not part of the ISO 20022 Business Transaction. If any such Message
Functionality is identified:
- Verify whether any existing ISO 20022 Message(s) offer(s) this Message
Functionality.
- Document which ISO 20022 Message(s) cover(s) this Message Functionality.
- Document Message Functionality that is not covered by any existing ISO 20022
Message Definition.
ƒ Compare the Message Functionality of the ISO 20022 Messages in the various ISO
20022 Business Transactions (or Message Flow Diagrams) with the Message
Functionality that is offered by the Industry Messages.
ƒ Document which Industry Message(s) cover(s) the Message Functionality of each
ISO 20022 Message in each ISO 20022 Business Transaction.
2 For each ISO 20022 Business Process that has been identified as one that matches a
Business Process of the Industry Message Set:
ƒ Identify any additional Business Transactions for which the Industry Messages are
currently used and that don’t exist yet in ISO 20022.
ƒ Document these additional Business Transactions (including the related Business
Process) based on the documentation of the Industry Message Set.
3 For each Business Process that has been identified as one that doesn’t exist yet in ISO
20022:
ƒ Identify the Business Transactions for which the Industry Messages are currently
used.
ƒ Document these Business Transactions (including the related Business Process)
based on the documentation of the Industry Message Set.
4 For each Business Transaction that has been identified in this step as one that doesn’t
exist yet in ISO 20022:
ƒ Identify the Message Functionality of all Industry Messages that are used.
ƒ Verify whether any existing ISO 20022 Message(s) offer(s) this Message
Functionality.
ƒ Document which ISO 20022 Message(s) cover(s) the additional Message
Functionality of the Industry Messages.
ƒ Document which Message Functionality of the Industry Message Set is not covered
by any existing ISO 20022 Message Definition.
Output:
• List of ISO 20022 Business Transactions – with reference to their ISO 20022 Business
Process and Business Area – that are covered by the Industry Message Set. This list will
include possible differences in definition that have been identified.

It is important to capture not only the individual message that is used but also to capture the business reason
why this message is used (i.e. the Message Functionality). Existing Industry Messages are namely often
“multi-functional” and both the gap analysis and the mapping documentation requires the identification of the
correct business message. Example: it’s not enough to state that the ISO 15022 MT 502 is used; one must also
clarify that it was for instance used as an “order to buy” or as an “order cancellation”.
• List of additional Business Transactions – with reference to their Business Process and
Business Area – that are not covered by any existing ISO 20022 Business Transactions.
• List of Industry Messages (including a particular Message Functionality in case the
Industry Message is multi-functional) and their corresponding ISO 20022 Messages – if
possible with reference to their ISO 20022 Business Transaction, Business Process and
Business Area.
• List of additional Message Functionality – with reference to their Business Transaction,
Business Process and Business Area – that is not covered by any existing ISO 20022
Messages.
4.1.5 Message Definition gap analysis
The goal is to identify ISO 20022 Message Definitions that are used in the Industry
Message Set and to investigate whether the Industry Message Set also has other Message
Definitions that are not yet covered by an ISO 20022 compliant Business Transaction and
Message Set.
Input:
• ISO 20022 Messages:
– Message Functionality
– Message Definition
– Message Rules.
• ISO 20022 Data Dictionary:
– Message Components (including Message Elements and Rules)
– Business Components (including Business Elements and Rules)
– Data Types.
6 7
• Industry Message Set documentation: definitions , formats and rules of all Industry
Messages and Industry Message Items.

One of the big challenges of this step is to identify the real business meaning of the fields.
Note that one Industry Message field may contain multiple Business Elements and/or may contain partial
Business Elements (in which case it may have to be combined with other Industry Message fields to obtain
meaningful Business Elements).
Note that a multi-functional Industry Message will also contain fields to specify the used functionality. These
fields won’t have a corresponding Message Element in the ISO 20022 Message. Document, for these fields,
the Message Functionality they represent.
Note that an Industry Message may contain “technical” fields, which have no business meaning. In some
cases, these fields may have a corresponding technical Message Element in the ISO 20022 Message
Definition but they will never have a corresponding Business Element.
The format is defined by the primitive Data Type + format constraints (e.g. a string, consisting only of
alphabetic characters and with a maximum length of 25; a set of Codes; etc.)
Activities:
The recommended approach for Message Definition gap analysis is depicted in the
following diagram and further explained in the text.
Industry
Message Functionality
Message
ISO 20022 •coverage
Set
Messages: •differences
documentation
• Definitions •gaps
• Elements
Search matching Message Definitions for
identified ISO 20022 Message Functionality
Document coverage in Message Items
Document differences in Message Items
Document gaps in Message Items
Search matching Business Elements for
additional Industry Message fields
Message Concept Business Concept
• coverage •coverage
• differences •differences
• gaps •gaps
1 For each ISO 20022 Message that has been identified as one that matches a Message of
the Industry Message Set:
ƒ Compare its Message Definition with the corresponding Industry Message
Definition. Take into account the used Message Functionality in case the Industry
Message is multi-functional. Also take into account any Message Rules.
ƒ Use the definitions of the ISO 20022 Message Concepts and their corresponding
Business Concepts and the documentation of the Industry Message Items to identify
equivalence and difference.
2 Document the coverage in Message Items:
ƒ List corresponding ISO 20022 Message Items (including the Message Component
and Message Path in the ISO 20022 Message) and Industry Message Items
(including the Message Path in the Industry Message).
ƒ Include the Business Element (and Business Component) that corresponds to the
Message Element.
3 Document the differences in Message Items:
ƒ List ISO 20022 Message Items (including the Message Component and path in the
ISO 20022 Message) and Industry Message Item (including the path in the Industry
Message) where the correspondence is not complete.
ƒ Include the Business Element (and Business Component) that corresponds to the
Message Element.
ƒ Document the differences. These differences can be related to:
ƒ the underlying business meaning
ƒ the used Data Type (primitive type, format and/or possible values)
ƒ the used Rules.
4 Document the gaps in Message Items:
• List the ISO 20022 Message Items (including the Message Component and path in
the ISO 20022 Message) for which no corresponding Industry Message Item exists.
• List the Industry Message Items (including the path in the Industry Message) for
which no corresponding ISO 20022 Message Item exists.
5 For all Industry Message Items for which no corresponding ISO 20022 Message Item
exists (note that this may include Industry Message Items from additional Industry
Message Functionality):
ƒ Search the ISO 20022 Data Dictionary to identify the Business Component and
Business Element that correspond to the meaning of the Industry Message Item.
ƒ If the corresponding ISO 20022 Business Component and Business Element
exist:
ƒ Document them
ƒ Identify differences or gaps regarding the Data Type and Rules and
document these as well.
ƒ If the corresponding ISO 20022 Business Component and/or Business Element
don’t exist:
ƒ Use the Industry Message Documentation to document the required
Business Component, Business Element, Data Type and Rules.
ƒ Note that a multi-functional Industry Message will also contain Industry Message
Items to specify the used functionality. These Industry Message Items won’t
necessarily have a corresponding ISO 20022 Message Element. Document for these
Industry Message Items the Message Functionality they represent.
Output:
• List of fully corresponding ISO 20022 Message Items and Industry Message Items,
including the Message Paths and the related Business Element and Business
Component.
• List of partially corresponding ISO 20022 Message Items and Industry Message Items,
including the Message Paths and the related Business Element and Business
Component. This list will also include a documentation of the identified differences
(meaning, data typing and/or rules)
• List of industry gaps (i.e. all ISO 20022 Message Items, including the Message Paths,
for which no corresponding Industry Message Item exists)
• List of ISO 20022 Message Concept gaps (i.e. all Industry Message Items, including the
Message Paths, for which no corresponding ISO 20022 Message Item exists).
• List of ISO 20022 Business Concept differences and gaps (i.e. all business concepts that
are covered by Industry Message Items but for which no corresponding ISO 20022
Business Concepts exist).
4.1.6 Business Roles gap analysis
The goal is to identify ISO 20022 Business Roles that appear in the Industry Message Set
and to investigate whether the Industry Message Set also covers other Business Roles that
are not yet covered by an ISO 20022 compliant Business Transaction and Message Set.
Note that some parts of this step can be executed earlier in the gap analysis, namely after
the Business Process gap analysis and after the Business Transaction gap analysis.
Input:
• ISO 20022 Business Roles definitions
• ISO 20022 Business Process descriptions, Business Process Diagram and Business
Activity Diagrams
• ISO 20022 Business Transaction documentation:
– Textual definition
– Message Flow Diagram, including message description
• Industry Message Set documentation related to Business Processes, Business
Transactions and Messages.
Activities:
The recommended approach for Business Roles gap analysis is depicted in the following
diagram and further explained in the text.
----------
...