EN 17952:2024

SLOVENSKI STANDARD
01-julij-2024
Upravljanje vrednosti - Analiza funkcij, osnovne značilnosti: Zahteve in navodila
za izvajanje in doseganje rezultatov
Value management - Function analysis, basic characteristics: Requirements and
guidance for implementation and achieving deliverables
Value Management - Funktionsanalyse, grundlegende Merkmale
Management par la Valeur - Analyse Fonctionnelle, caractéristiques fondamentales :
Exigences et recommandations pour la mise en œuvre et la réalisation des livrables
Ta slovenski standard je istoveten z: EN 17952:2024
ICS:
03.100.40 Raziskave in razvoj Research and development
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 17952
EUROPEAN STANDARD
NORME EUROPÉENNE
June 2024
EUROPÄISCHE NORM
ICS 03.100.40
English Version
Value Management - Function Analysis: Basic
characteristics, requirements and guidance for
implementation
Management par la valeur - Analyse Fonctionnelle: Value Management - Funktionenanalyse: Grundlegende
caractéristiques fondamentales, exigences et Merkmale, Anforderungen und Leitlinien für die
recommandations pour la mise en œuvre Umsetzung
This European Standard was approved by CEN on 27 February 2024.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

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United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2024 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 17952:2024 E
worldwide for CEN national Members.

Contents Page
European foreword . 4
Introduction . 5
1 Scope . 8
2 Normative references . 9
3 Terms, definitions and abbreviated terms . 9
4 Function Analysis overview . 14
4.1 Context for Function Analysis . 14
4.2 Function Analysis: a system approach . 15
4.3 Function Analysis with its two distinct areas . 16
4.3.1 General. 16
4.3.2 Functional Need Analysis . 19
4.3.3 Technical Function Analysis . 20
4.4 Essential conditions for successful Function Analysis . 21
4.4.1 Essential Conditions for success . 21
4.4.2 Roles and contributions of the involved people . 21
4.5 Function Thinking . 22
5 Application of Function Analysis . 22
5.1 General. 22
5.2 Level of analysis . 23
5.2.1 General. 23
5.2.2 Top Management level of the organization: Vision and Strategy . 23
5.2.3 Management level . 23
5.2.4 Operational level . 24
5.2.5 Day-to-Day Management . 24
5.3 Integrating with other Disciplines . 24
5.3.1 Risk management and Dependability . 24
5.3.2 Sourcing and Procurement . 25
5.3.3 Systems and Software Engineering . 25
5.3.4 Innovation Management . 25
5.3.5 Organization corporate social responsibility . 26
6 Requirements for effective application of Function Analysis . 26
6.1 General. 26
6.2 Scope study. 27
6.3 Identify functions and constraints . 28
6.4 Organize the functions . 30
6.5 Characterize the functions . 30
6.6 Prioritizing the functions . 31
6.7 Estimating efficiency of potential solutions . 31
7 Requirements applicable to Function Analysis deliverables. 32
7.1 General. 32
7.2 Requirements applicable to Functional Need Analysis (FNA) deliverables . 32
7.2.1 General. 32
7.2.2 Study Scope . 32
7.2.3 Description of the overall need. 33
7.2.4 Search for identification and description of functions . 34
7.2.5 Contribution to the definition and validation of the solution . 37
7.2.6 Use of Functional Need Analysis. 39
7.3 Requirements applicable to Technical Function Analysis (TFA) deliverables . 39
7.3.1 General . 39
7.3.2 Expected contributions . 39
7.3.3 Study Scope . 40
7.3.4 Description of the need to be satisfied . 40
7.3.5 Description of functions . 40
7.3.6 Contribution to the definition and validation of the solution . 43
7.3.7 Use of Function Analysis for market testing and Competitive Advantage . 46
Annex A (informative) Guidance applicable to the approach and methods of Function
Analysis . 48
Bibliography . 57

European foreword
This document (EN 17952:2024) has been prepared by Technical Committee CEN/TC 279 “Value
management, value analysis, function analysis”, the secretariat of which is held by BSI.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by December 2024, and conflicting national standards
shall be withdrawn at the latest by December 2024.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
Any feedback and questions on this document should be directed to the users’ national standards body.
A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organisations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and the
United Kingdom.
Introduction
This document sets out requirements for Function Analysis (FA). FA is used to define and validate
needs, prioritize requirements, assess performance, stimulate innovation, guide design and support
procurement and inform decisions to use, reuse, and recycle parts and products.
FA provides people in different fields of application with a proven method for defining needs,
developing an offer, improving purchases, contracting a partnership or increasing the efficiency of
activities. FA is a process that describes completely the functions and their relationships which are
systematically characterized, classified and evaluated.
0.1 General
The purpose of this document is to provide effective support to any person or organization wishing to
improve its effectiveness or performance or operational activities and in the definition, development or
the realization of any action or project.
FA makes an effective contribution in fields of quality management (EN ISO 9001), environmental
management systems (EN ISO 14001), configuration management (ISO 10007, EN 9223-100),
dependability management (EN 60300-1), circular economy (EN 62309), systems and software
engineering (ISO/IEC/IEEE 15288) and performance management. It is essential for Value Management
(EN 12973) and successful application of a Functional Performance Specification (EN 16271).
FA involves and relies upon a way of thinking, based on a continuous process, with or without a
dedicated team, that encourages the search for the goal and the need to be fulfilled, before looking for
ways to achieve it that applies at any level and in any process.
FA firstly, defines the objective in a concise and clearly expressed way, independent of any solution, and
secondly, provides support and assistance in the process to effectively achieve the defined need. FA
activities support enhanced teamwork, assists in gaining a consensus agreement and collaboration in
the collective pursuit of the chosen goal.
FA is a standalone method and is used by many disciplines, for example, concurrent or simultaneous
engineering, systems and software engineering and risk management. This document specifies that the
practice of FA meets specific requirements to ensure the validity of the expected results in the intended
usage context. FA is a fundamental component in improving performance of organizations, allowing the
pursuit of opportunities while identifying and significantly reducing threats throughout the life cycle.
FA is linked to Value Management, Value Analysis and Value Engineering. FA is a specific method; it
should not be confused with classic methods such as the Functional Analysis in applied mathematics.
This document describes the global structure of FA, how it is situated in the organizational environment
and how it links to other management and engineering practices.
In addition, it provides recommendations for the implementation of commonly used FA methods and
tools (Annex A).
0.2 Function Analysis at the heart of Management
For any management activity it is imperative to differentiate systematically the two distinct areas, in
one area, the goal to be achieved (the objective) and need to be met, using Functional Need Analysis
(FNA) and in the other area, the way to achieve it (the means and resources, the process or the solution)
using Technical Function Analysis (TFA).
FA, with its two distinct areas, provides an effective and strong methodological support at any level and
in any field, when dealing with challenges of whatever complexity. It could be used for example, in
strategic planning, business and project management, product and market development, or in any
process of problem solving. It provides you with the opportunity to improve the performance of your
organization.
0.3 Contributions for the different users of the standard
FA helps different users to clarify and define problems of any kind that concern an organization, thus
contributing to their definition and resolution.
The benefits from effectively applying Functional Need Analysis include:
— the identification and description, in a concise language, without any ambiguity, the need to be
satisfied for a given study subject (the aim to be reached); and
— the assurance of improved communication between everyone in the team involved in the project,
within a common vision, free from unnecessary specialist jargon.
The benefits of the TFA include:
— a controlled traceability between the identified need and how this is satisfied by the proposal or
solution;
— the supply of rational choices for a solution, supported by the identification and evaluation of the
benefits and impacts induced and an assessment of the ability to meet the identified need; and
— a systematic method to facilitate the treatment of complexity, risk and uncertainty.
0.4 Key roles and responsibilities
A prerequisite for FA lies in the clarity of the roles, field of activity and the responsibilities of each
person involved, whether formalized or not.
In the case of a FA action, the following roles are fundamental:
— the “Decision-maker”, who defines the purpose, objectives, resource allocation and ultimately will
be responsible for decision-making, the definition of the need and for the specified objective, which
procures the resources;
— the “FA Project Leader” or facilitator, person who is responsible for selecting the FA approach,
methods and tools and who has the knowledge, competence, and personality to organize, lead and
coordinate a FA team in a professional and successful way, and as such has been put in charge of
this responsibility by management; and
— the “FA team”: chosen for their knowledge of the subject, the object of the action, which could be
integrated within any team.
FA can be used continuously as an effective support for any reflection.
0.5 The two distinct areas of Function Analysis
FA assists in interrogating a challenge in two distinct areas, firstly by clarifying the goal to be achieved
and need to be met, and secondly, by searching, researching and establishing the best solution to the
identified need and goal.
FA applies to all processes and tasks, involving contributors inside and outside the organization. It
requires setting aside technical solutions to understand and interpret the objectives and aims of the
proposed action in order to promote creativity in the search and evaluation of the solutions.
FA enables:
— the identification of the functions of any object such as a product or an organization;
— the quantification of the performances to be achieved;
— communication between all the people in a multidisciplinary team involved in the project with a
common language;
— the identification of the principles of solutions and the benefits, impacts and risks which they
generate;
— the establishment of the required performances of the solution providing a basis for the
establishment of a Product Function Architecture;
— the evaluation of the capacity of a product to meet the expressed need; and
— a common understanding of the challenge posed and potential solutions considered to solve it.
This is why FA, as a process, has its place upstream, alongside and downstream of any project. FA result
is the input datum in processing of any problem (the issue to resolve): be it evolution, creation,
innovation, dysfunction, obsolescence, etc., for which one wishes to obtain the most effective response
to satisfy the expressed need, while dispensing with a priori solutions.
Functional Need Analysis (FNA area) identifies the User Related Functions (URFs) and is intended to
take into account all the needs and expectations of the different users, customers and selected
stakeholders that are interested in the product throughout its life cycle.
Technical Function Analysis (TFA area) identifies the Product Related Functions (PRFs) and defines a
Function Structure, provides a logical description of the technical functions and their relationships in
order to examine alternatives and to propose a solution.
From an economic point of view, FA has proven to be very useful, if not essential, as it improves the
return on investment which can be achieved (with shorter development time, improved performance
obtained, adequacy of solutions to the expressed need, etc.), even if an existing or potential solution
may often suffice.
FA, when timely and appropriately applied, assists in achieving the most appropriate proposal or
potential solution.
FA, with its method and tools, is referenced in Value Management (EN 12973) and Functional Need
Expression and the Functional Performance Specification (EN 16271). Additionally, European Union
(EU) directives such as the EU Public Procurement Directive 2014/24 and update notices, have also
encouraged the market in the wider use of the Functional Performance Specification.
0.6 Conditions for success
The participants in any FA action need to be familiar with the general area of application. In order to be
efficient, the FA team will be aware that the success lies in the clarity of the roles, field of activity and
the responsibilities of each person involved, whether formalized or not. An organization that
implements the FA approach is liable to see the creative skills of their people improve which should
enhance their organization’s competitiveness. FA can be integrated into in any process in an
organization.
The people involved are required to follow a path which allows scope for creativity in the pursuit of the
appropriate solution. It is important to measure the effectiveness of the team over time with respect to
the project or action type. Some people may need to be familiar with the area of activity for which an
action is required. The range of applications that can be assessed are infinite, with a particular choice of
action based on priority and the availability of skilled staff that are familiar with the FA approach.
0.7 Function Thinking
There is “Function Thinking” capability when people are able to first, in a reflective way, think of the
purpose of any action, before, second, seeking a solution, while doing this in a formal or informal way.
1 Scope
This document presents Function Analysis (FA) and specifies requirements for Function Analysis and
its deliverables. It presents the two distinct areas of application, namely, Functional Need Analysis
(FNA) relating to understanding the need, setting goals and Technical Function Analysis (TFA) relating
to selecting and developing a solution. It specifies requirements for the basic characteristics of the
deliverables within FNA and TFA and expands requirements, guidance and recommendations about FA
expressed in the Functional Performance Specification Standard (EN 16271) and in the Value
Management Standard (EN 12973).
This document provides an essential reference and support for any person wishing to improve the
efficiency, effectiveness and overall performance of their organization. It aims to support sustainable
development in an organization. FA offers an opportunity to enhance skills of people involved.
In order to present the conditions for implementation and development of FA deliverables, this
document:
• introduces the interests and fields of application and presents a variety of situations in which FA is
used in support of projects of all types and sizes;
• specifies essential conditions for successful FA, including roles and responsibilities of the people
involved, monitoring the performance of the FA team, processes for validation and verification and
supply of valid and verified deliverables; and
• specifies requirements for FA and the basic characteristics of FA deliverables whilst outlining
methods, and tools for the realization of the deliverables.
FA is progressed using the following:
• FNA: support for the process of identifying and understanding the need, defining objectives, and
setting the goal to be achieved;
• TFA: support for design or research processes and evaluation of solutions; and
• Iteratively focusing on the FNA and TFA by revisiting the identified need, balancing capabilities of
available technologies, resources and constraints, achieving the most desirable outcome.
In the area of FNA, this document sets out FNA requirements for the deliverables to establish the
Functional Need Expression (FNE). The FNE can serve as a basis for establishing an understanding of
the expressed need, the complete list of User Related Functions (URFs), constraints and interfaces.
These deliverables serve as a basis for identifying, organizing, characterizing and prioritizing functions
and function interfaces. These deliverables can also support preliminary risk and reliability studies,
economic studies, impact assessments and development of Functional Performance Specifications
(FPSs).
In the area of TFA, this document sets out requirements for TFA deliverables which aim to satisfy the
need, expressed in the FNE. The TFA deliverables are focused on analysing existing and potential
solutions, identifying a complete list of the Product Related Functions (PRFs) to meet the FNE;
evaluating concepts and making a choice for a solution then optimizing the Product Function
Architecture (PFA) to identify the “best” solution.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
EN 16271, Value management - Functional expression of the need and functional performance
specification - Requirements for expressing and validating the need to be satisfied within the process of
purchasing or obtaining a product
EN 12973, Value Management
EN 1325, Value Management - Vocabulary - Terms and definitions
3 Terms, definitions and abbreviated terms
For the purposes of this document, terms and definitions given in EN 1325 and the following apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obp
— IEC Electropedia: available at https://www.electropedia.org/
3.1 Terms and definitions
3.1.1
customer
person or organization who has the potential to be a user of a product at any time during its life cycle
[SOURCE: EN 1325:2014, 2.1.3]
3.1.2
user
person or organization for which the product is designed and which exploits at least one of its functions
at any time during its life cycle
Note 1 to entry: A user can be an external or internal customer.
[SOURCE: EN 1325:2014, 2.1.4]
3.1.3
stakeholder
person or organization which has an interest in and influence on a product at any time during its life
cycle
[SOURCE: EN 1325:2014, 2.1.2]
3.1.4
decision-maker
entity or member of an organization who gives scope to the Function Analysis project and is the
ultimate decision-maker of the chosen proposals of the Function Analysis (FA) team which will be
implemented
3.1.5
function analysis team
multidisciplinary group of people, selected for their competence, expertise and responsibility in various
aspects of the Function Analysis subject being studied
3.1.6
function analysis project leader
person who has the knowledge, competence, and personality to organize, lead and coordinate a
Function Analysis (FA) team in a professional and successful way, and as such has been put in charge of
this responsibility by management
3.1.7
enquirer
person or organization in search of a product and which is responsible for issuing the Functional
Performance Specification, with a view to its purchase or acquisition and use by itself or by others
[SOURCE: EN 1325:2014, 2.2.4.2]
3.1.8
product
result of activities or processes, any goods, supplies, process, service, system, strategy or organization
Note 1 to entry: A product can include service, hardware, processed materials, software or a combination thereof.
Note 2 to entry: A product can be tangible (e.g. assemblies or processed materials) or intangible (e.g. knowledge
or concepts), or a combination thereof, or a temporary endeavour (e.g. project created to produce agreed
deliverables).
Note 3 to entry: A product can be either intended (e.g. offering to customers) or unintended (e.g. pollutant or
unwanted effects).
Note 4 to entry: A product can be a project.
[SOURCE: EN 1325:2014, 2.1.5, Note 2 modified, Note 4 added.]
3.1.9
need
what is necessary for or desired by the, Users, Customers and other Stakeholders
Note 1 to entry: A need can be declared or undeclared; it can be existing or potential.
[SOURCE: EN 1325:2014, 2.1.8, modified.]
3.1.10
function
effect of a product or of one of its constituents
Note 1 to entry: Functions should be expressed in an abstract form, free of solutions.
Note 2 to entry: In some contexts, the function of a product may be recognized as mode of action or activity by
which a product fulfils its purpose.
[SOURCE: EN 1325:2014, 2.3.1.1, modified, Note 2 added.]
3.1.11
user related function
URF
effect expected of a product, or to be performed by it, in order to meet a part of the need of a user
Note 1 to entry: Users and the market are only interested in User Related Functions.
Note 2 to entry: Customer needs and specifications may be expressed as a set of User Related Functions.
Note 3 to entry: The term “External Function” used in certain professional circles can be considered synonymous.
Note 4 to entry: User Related Functions might be either necessary or unnecessary, desirable or undesirable.
Functional Need Analysis (FNA) is a method which helps to eliminate unnecessary and undesirable functions.
[SOURCE: EN 1325:2014, 2.3.1.4.1, Modified, Original Note 3 deleted and new Note 3 added and new
Note 4 added.]
3.1.12
product related function
PRF
effect of a constituent of a product or the effect between the constituents of the product for the purpose
of performing User Related Functions
Note 1 to entry: When choosing an overall solution, the designer or organizer determines the Product Related
Functions sometimes called internal functions.
Note 2 to entry: The Product Related Functions of a complete product can constitute the User Related Functions
of a component element of the product.
Note 3 to entry: The Product Related Functions can be related to the available technology.
Note 4 to entry: A Product Related Function might be either necessary or unnecessary, desirable or undesirable.
Note 5 to entry: This document, in accordance with established practice, uses the term “Product Related
Function”; the term “Internal Function and Technical Function” used in certain professional circles can be
considered synonymous.
[SOURCE: EN 1325:2014, 2.3.1.4.2, modified, Note 5 added.]
3.1.13
function analysis
FA
process that describes completely the functions and their relationships, which are systematically
characterized, classified and evaluated
Note 1 to entry: The Function Structure is a part of the result of Function Analysis.
Note 2 to entry: Function Analysis covers two distinct areas: The Functional Need Analysis (or External Function
Analysis) and the Technical Function Analysis (or Internal Function Analysis).
[SOURCE: EN 1325:2014, 2.3.1, modified, Note 2 revised and Note 3 deleted.]
3.1.14
functional need analysis
FNA
part of Function Analysis which describes the need that the product shall satisfy in the form of User
Related Functions and constraints
Note 1 to entry: Sometimes referred to as 'External Function Analysis' or ‘Customer Function Analysis’.
[SOURCE: EN 1325:2014, 2.3.1.2, Note 1 modified.]
3.1.15
functional need expression
FNE
result of a Functional Need Analysis
Note 1 to entry: The Functional Need Expression is used as a basis to draw up the main part of the Functional
Performance Specification.
Note 2 to entry: Obtaining a product may comprise acquisition, exploratory studies, or development followed by
supply.
[SOURCE EN 1325:2014, 2.3.3.1]
3.1.16
technical function analysis
TFA
part of Function Analysis which contributes to studying and formalizing the Product Function
Architecture by identifying the Product Related Functions
Note 1 to entry: The term “Internal Function Analysis” used in certain professional circles can be considered
synonymous.
Note 2 to entry: The term “Performance Function Analysis” used in certain professional circles can be considered
synonymous.
Note 3 to entry: A Technical Function Analysis helps to explain how a product works and what it does to satisfy
the need.
[SOURCE: EN 1325:2014, 2.3.1.3, modified, specific reference to sub-assemblies and components
removed as these are part of the product, Note 1 revised and Notes 2 and 3 added.]
3.1.17
function structure
arrangement of functions resulting from Function Analysis, which can be presented in the forms of a
tree, or of a diagram, for example, giving a complete, visual, written presentation
Note 1 to entry: When Product Related Functions are considered, the Function Structure shows the way in which
the functions interact.
[SOURCE: EN 1325:2014, 2.3.1.5]
3.1.18
product function architecture
deliverable result of the Technical Function Analysis (TFA) activity established by the designer, listing
all the constituents of a solution
Note 1 to entry: Product Function Architecture is concerned with product decomposition and is described by the
Product Related Functions, their relationship, the arrangement of product constituents.
Note 2 to entry: Product Function Architecture is a potential output as a result of the Technical Function Analysis,
it depends on the nature of the action and the subject studied.
3.1.19
constraint
characteristic result or design feature which is made compulsory or has been prohibited for any reason,
with no alternative possibility being left
Note 1 to entry: Constraints are generally restrictions on the choice of the solutions.
Note 2 to entry: The constraints can result from laws, from standards, from the demand of the market. These
elements contribute to the characterization of the functions.
Note 3 to entry: Given the importance which the constraints can have on the definition of the product, it is good
practice to justify any specified constraint.
Note 4 to entry: To facilitate the reading of the results of the Function Analysis, constraints can be included in a
particular section of the Functional Need Expression.
[SOURCE: EN 16271:2012, 3.4, Notes 1 and 2 modified.]
3.1.20
granularity
definition of the fineness, detail level, richness of the elementary information chosen to perform
Function Analysis
Note 1 to entry: Granularity needs to be chosen carefully; insufficient detail will result in vagueness. Too much
detail may implicitly impose types of solution, restrict the search field, and it may require hardly justifiable work.
[SOURCE: EN 1325:2014, 2.3.3.2, modified to reference Function Analysis rather than Functional Need
Expression and Notes 2 and 3 deleted.]
3.2 Abbreviated terms
EN – English term FR – French term DE – German term
FA Function Analysis AF Analyse Fonctionnelle FA Funktionenanalyse
Analyse Fonctionnelle du Funktionenanalyse von
FNA Functional Need Analysis AFB FAB
Besoin Bedürfnissen
FNE Functional Need Expression EFB Expression Fonctionnelle du FBB Funktionale Beschreibung
Besoin von Bedürfnissen
FPS Functional Performance CDCF Cahier des Charges FLB Funktionale
Specification Fonctionnel Leistungbeschreibung
FS Function Structure SF Structure fonctionnelle FS Funktionenstruktur
PFA Product Function AFP Architecture Fonctionnelle FAP Funktionale Architektur des
Architecture du Produit Produkts
PRF Product Related Function FT Fonction Technique PBF Produktbezogene Funktion
EN – English term FR – French term DE – German term
TFA Technical Function Analysis AFT Analyse Fonctionnelle TFA Technische
Technique Funktionenanalyse
URF User Related Function FS Fonction de Service NBF Nutzerbezogene Funktion
4 Function Analysis overview
4.1 Context for Function Analysis
This subclause describes the various aspects of Function Analysis (FA).
Whenever management is faced with making a decision, the starting point is not the way in which the
challenge will be solved, but rather what goal is to be achieved. The need and expected objectives of
users, customers and other stakeholders should be translated into clearly identified functions.
The subject may relate to any work, at any stage of it, from its beginning to its end, whether it be for
example, on a Vision, a Mission, a Strategy, a project, process or a product, including for example the
related design, development, marketing, delivery and use.
Situations often present some degree of complexity which requires to be resolved.
FA should be used to resolve:
• interactions between people and constituents of a product, the subject of the action;
• conflicting opinions in a context of uncertainty about objectives; and
• individual processes and multiple paths to achieve success.
A search for function (existing effects, desirable effects and necessary effects) bears fruit in situations
which are irrational, unpredictable and chaotic as well as in well-defined simple and complicated
situations. The analysis of function, and the logical pathways which relate functions, builds
understanding from multiple perspectives to establish consensus around objectives and to recognize
the effects of uncertainty.
The path of any action or subject for reflection, should follow a logical path, whether explicitly or not,
respecting the following steps:
— define and delineate the purpose of the project or product;
— complete and define an objective, conscious and independent of prior solutions in seeking out a
new solution (Functional Need Analysis);
— carry out a “critical analysis” of the existing situation or proposed solution (Technical Function
Analysis);
— explore creativity working with both the Technical Function Analysis (TFA) and the Functional
Need Analysis (FNA) to develop an original solution; and
— lead to proposal selection, approval and implementation by the Decision-maker.
Consideration should be given to the methods and tools to identify clearly and completely these
functions, and the required performance (assessment criteria, levels, flexibility) to meet market
conditions.
The objective to be reached is described by the set of performances outlined in the Functional Need
Expression and, if useful, in a Functional Performance Specification (FPS). Then the solution or proposal
can be developed, using the TFA and is described as the Product Function Architecture. The outputs of
FNA and the TFA are called the “deliverables”.
Furthermore, the constraints applicable to the subject under development should be expressed in a
clear, concise, and unambiguous way, and made readily accessible at any time for those concerned.
4.2 Function Analysis: a system approach
Function Analysis (FA) is a global approach with the subject seen as a whole entity based on purposes
rather than causalities.
For any project, the purpose to be achieved by the product, can be considered as the “identified need”
provided by the complete set of User Related Functions (URFs) for the customers, users and other
selected stakeholders and provided by a solution defined by a set of Product Related Functions (PRFs).
The solution shall also comply with the applicable constraints.
FA is a holistic method that means that it encompasses the entire environment of the product and the
situations it encounters and impacts during its complete life cycle.

Key
A Traditional approach: object (i.e. the subject of the action) defined by itself and for itself; analysis of
interactions between constituents referring to existing solutions.
B Function Analysis approach: object defined by its environment; use and performance to be provided to
the various users, customers and other stakeholders; satisfaction of expectations; examination of effect.
The white lines represent interactions involving the object to satisfy the need. The black lines represent
interactions with the object.
Figure 1 — Function Analysis: a “system” approach
As shown in Figure 1, the traditional approach focuses on the analysis of the object, its constituents, its
mode of operation, etc.
The function approach begins by defining the object by positioning it in its environment, while defining
the intended use and performance to be delivered. For this, the approach leads to identify reciprocal
relationships (for example, actions, interactions) in the form of URFs.
Then, and only then, it identifies the solution concepts able to perform the functions and proceeds to
their study (composition, operation, support, etc.).
4.3 Function Analysis with its two distinct areas
4.3.1 General
The function expresses the effect of an object or one of its constituents in satisfying the need of an
identified user. This need is specified in a later stage of the process with indications of performance (e.g.
levels and flexibilities). These simple concepts give to Function Analysis (FA) a significant added value.
Always consider the two distinct areas of FA:
a) On one hand, the Functional Need Analysis (FNA) helps to explain the need (to which the studied
project or product should provide), the deliverable being the Functional Need Expression (FNE).
This FNE could provide a basis for establishing a Functional Performance Specification (FPS).
b) On the other hand, the Technical Function Analysis (TFA) helps to imagine or model solution
principles, the deliverable being the Product Function Architecture. This architecture relates to the
product, solution or proposal imagined or described, including the principles adopted (concepts,
physical and organizational principles, etc.).
FA describes the user's need to the extent required: It allows for the identification of the User Related
Functions (URFs) and their relationships.
This is achieved by seeking, ordering, characterizing, weighting, prioritizing and ass
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