SIST EN 60706-2:2007

SLOVENSKI STANDARD
SIST EN 60706-2:2007
01-januar-2007
Vzdrževalnost opreme - 2. del: Zahteve za vzdrževalnost in študije vzdrževalnosti v
fazi snovanja in razvoja (IEC 60706-2:2006)
Maintainability of equipment -- Part 2: Maintainability requirements and studies during the
design and development phase
Instandhaltbarkeit von Geräten -- Teil 2: Instandhaltbarkeitsanforderungen und Studien
in der Entwicklungsphase
Maintenabilité de matériel -- Partie 2: Exigences et études de maintenabilité pendant la
phase de conception et de développement
Ta slovenski standard je istoveten z: EN 60706-2:2006
ICS:
03.100.40 Raziskave in razvoj Research and development
21.020 =QDþLOQRVWLLQQDþUWRYDQMH Characteristics and design of
VWURMHYDSDUDWRYRSUHPH machines, apparatus,
equipment
SIST EN 60706-2:2007 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN 60706-2:2007

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SIST EN 60706-2:2007


EUROPEAN STANDARD
EN 60706-2

NORME EUROPÉENNE
June 2006
EUROPÄISCHE NORM

ICS 03.120.01; 21.020


English version


Maintainability of equipment
Part 2: Maintainability requirements and studies
during the design and development phase
(IEC 60706-2:2006)


Maintenabilité de matériel  Instandhaltbarkeit von Geräten
Partie 2 : Exigences et études de Teil 2: Instandhaltbarkeitsanforderungen
maintenabilité pendant la phase de und Studien in der Entwicklungsphase
conception et de développement (IEC 60706-2:2006)
(CEI 60706-2:2006)




This European Standard was approved by CENELEC on 2006-05-01. CENELEC 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 Central Secretariat or to any CENELEC 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 CENELEC member into its own language and notified
to the Central Secretariat has the same status as the official versions.

CENELEC members are the national electrotechnical committees of Austria, Belgium, Cyprus, the Czech
Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and the United Kingdom.

CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung

Central Secretariat: rue de Stassart 35, B - 1050 Brussels


© 2006 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 60706-2:2006 E

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SIST EN 60706-2:2007
EN 60706-2:2006 - 2 -

Foreword
The text of document 56/1090/FDIS, future edition 2 of IEC 60706-2, prepared by IEC TC 56,
Dependability, was submitted to the IEC-CENELEC parallel vote and was approved by CENELEC as
EN 60706-2 on 2006-05-01.
The following dates were fixed:
– latest date by which the EN has to be implemented
at national level by publication of an identical
(dop) 2007-02-01
national standard or by endorsement
– latest date by which the national standards conflicting
(dow) 2009-05-01
with the EN have to be withdrawn
Annex ZA has been added by CENELEC.
__________
Endorsement notice
The text of the International Standard IEC 60706-2:2006 was approved by CENELEC as a European
Standard without any modification.
In the official version, for Bibliography, the following notes have to be added for the standards indicated:
IEC 60300-1 NOTE  Harmonized as EN 60300-1:2003 (not modified).
IEC 60300-2 NOTE  Harmonized as EN 60300-2:2004 (not modified).
IEC 60300-3 NOTE  Harmonized in 60300-3 series (not modified).

__________

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SIST EN 60706-2:2007
- 3 - EN 60706-2:2006

Annex ZA
(normative)

Normative references to international publications
with their corresponding European publications

The following referenced documents are indispensable for the application 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.

NOTE  When an international publication has been modified by common modifications, indicated by (mod), the relevant EN/HD
applies.

Publication Year Title EN/HD Year

IEC 60050-191 1990 International Electrotechnical Vocabulary - -
(IEV)
Chapter 191: Dependability and quality of
service


1) 2)
IEC 60300-3-1 - Dependability management EN 60300-3-1 2004
Part 3-1: Application guide - Analysis
techniques for dependability - Guide on
methodology


1) 2)
IEC 60300-3-3 - Dependability management EN 60300-3-3 2004
Part 3-3: Application guide - Life cycle costing


IEC 60300-3-10 2001 Dependability management - -
Part 3-10: Application guide - Maintainability


1)
IEC 60300-3-11 - Dependability management - -
Part 3-11: Application guide - Reliability
centred maintenance


1) 2)
IEC 60300-3-12 - Dependability management EN 60300-3-12 2004
Part 3-12: Application guide - Integrated
logistic support


1) 2)
IEC 60300-3-14 - Dependability management EN 60300-3-14 2004
Part 3-14: Application guide - Maintenance
and maintenance support


1)
IEC 60706-3 - Maintainability of equipment - -
Part 3: Verification and collection, analysis
and presentation of data


1)
IEC 60706-5 - Guide on maintainability of equipment - -
Part 5 - Section 4: Diagnostic testing


1) 2)
IEC 60812 - Analysis techniques for system reliability - EN 60812 2006
Procedure for failure mode and effects
analysis (FMEA)


1) 2)
IEC 61025 - Fault tree analysis (FTA) HD 617 S1 1992


1) 2)
IEC 61160 - Design review EN 61160 2005



1)
Undated reference.
2)
Valid edition at date of issue.

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SIST EN 60706-2:2007
EN 60706-2:2006 - 4 -
Publication Year Title EN/HD Year
IEC 61649 1997 Goodness-of-fit tests, confidence intervals - -
and lower confidence limits for Weibull
distributed data

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SIST EN 60706-2:2007
NORME CEI
INTERNATIONALE
IEC



60706-2
INTERNATIONAL


Deuxième édition
STANDARD

Second edition

2006-03


Maintenabilité de matériel –
Partie 2:
Exigences et études de maintenabilité
pendant la phase de conception et
de développement

Maintainability of equipment –
Part 2:
Maintainability requirements and studies
during the design and development phase

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International Electrotechnical Commission
МеждународнаяЭлектротехническаяКомиссия
Pour prix, voir catalogue en vigueur
For price, see current catalogue

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SIST EN 60706-2:2007
60706-2  IEC:2006 – 3 –
CONTENTS
FOREWORD.7
INTRODUCTION.11

1 Scope.13
2 Normative references .13
3 Terms, definitions and acronyms .15
3.1 Terms and definitions .15
3.2 Acronyms .17
4 General approach.17
5 Principle of maintainability.19
6 Maintainability activities in the life cycle .19
6.1 General .19
6.2 Concept and definition phase .21
6.3 Design and development phase.21
6.4 Manufacture and installation phase .23
6.5 Operation and maintenance phases .23
6.6 Disposal phase.23
7 Specification of maintainability requirements .25
7.1 Statement of maintainability requirements .25
7.2 Maintainability characteristics.27
7.3 Constraints.31
7.4 Maintainability programme requirements .33
7.5 Verification .33
8 Maintainability studies in the design and development phase .35
8.1 General .35
8.2 Objectives .35
8.3 Maintainability studies in the design process .35
8.4 Analysis tools and procedures.45
9 Design support .59
9.1 Liaison .59
9.2 Design criteria and check-lists.61
9.3 Design reviews.63

Annex A (informative) Maintainability allocation .67
Annex B (informative) Example of a maintainability allocation .81
Annex C (informative) Example of allocation of reliability values and maintenance
strategy selection for a system with non-constant failure rate .87

Bibliography.101

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SIST EN 60706-2:2007
60706-2  IEC:2006 – 5 –
Figure 1 – Maintainability studies in the design process.41
Figure 2 – Hardware level maintainability block diagram .49
Figure 3 – Basic steps in maintainability prediction .53
ACMT ACMT
 
50 95
Figure A.1 – = f .77
 
MACMT MACMT
 
Figure A.2 – Maintainability allocation to sub-item level .79
Figure B.1 – Functional level diagram .83
Figure C.1 – Weibull plot of the components in the system .99


Table 1 – Examples of quantitative maintainability characteristics.27
Table 2 – Detailed tasks in maintainability studies .43
Table A.1 – M allocation to sub-item level.75
Table B.1 – Allocation table .85
Table C.1 – Comparison of costs .97

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SIST EN 60706-2:2007
60706-2  IEC:2006 – 7 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________

MAINTAINABILITY OF EQUIPMENT –

Part 2: Maintainability requirements and studies
during the design and development phase


FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with an IEC Publication.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 60706-2 has been prepared by IEC technical committee 56:
Dependability.
This second edition cancels and replaces the first edition, published in 1990, and constitutes
a technical revision.
The major technical changes with regard to the first edition concern the inclusion of the
original Section Two from IEC 60706-1:1982 entitled: Maintainability requirements in speci-
fications and contracts, as well as the original mathematical Annex A from IEC 60706-6:1994,
entitled Maintainability allocation.

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SIST EN 60706-2:2007
60706-2  IEC:2006 – 9 –
The text of this standard is based on the following documents:
FDIS Report on voting
56/1090/FDIS 56/1101/RVD

Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
IEC 60706 consists of the following parts, under the general title Maintainability of equipment:
NOTE Each part outlines the application of specific techniques to implement a maintainability programme.
Part 1: Introduction, requirements and maintainability programme
Part 2: Maintainability requirements and studies during the design and development phase
Part 3: Verification and collection, analysis and presentation of data
Part 4: Guide to maintenance and maintenance support planning
Part 5: Diagnostic testing
Part 6: Statistical methods in maintainability evaluation

The committee has decided that the contents of this publication will remain unchanged until
the maintenance result date indicated on the IEC web site under "http://webstore.iec.ch" in
the data related to the specific publication. At this date, the publication will be
• reconfirmed;
• withdrawn;
• replaced by a revised edition, or
• amended.

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SIST EN 60706-2:2007
60706-2  IEC:2006 – 11 –
INTRODUCTION
Maintainability is a characteristic that defines the ease with which an item can be maintained
and supported during its period of use. Maintainability has to be built into an item during the
design and development phase and it is therefore important that maintainability requirements
be established as part of the initial specification.
The IEC 60706 series of standards is intended to give guidance on how a designer should
best incorporate high standards of maintainability into a product so that the cost of
maintenance is reduced to an acceptable level. It is also important to ensure that the
necessary maintenance can be undertaken to keep the product in a safe condition and that it
can be operated to its required performance.
This International Standard gives an introduction to the concept of maintainability, and
guidance as to how maintainability can be incorporated into specifications and contracts and
how maintainability should be considered as part of the design process. It forms part of a
hierarchy of standards on dependability as described below.
IEC 60300-1 and IEC 60300-2 are the IEC top-level standards that provide guidance on how
to incorporate dependability, including reliability, availability and maintainability, into
manufactured products. IEC 60300-3-10 is the top-level standard on maintainability, serving
as an application guide and which forms part of the IEC 60300-3 series of standards. It can be
used to implement a maintainability programme covering the initiation, development and in-
service phases of a product, which form part of the tasks described in IEC 60300-2. It also
provides guidance on how the maintenance aspects of the tasks should be considered in
order to achieve optimum maintainability.

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SIST EN 60706-2:2007
60706-2  IEC:2006 – 13 –
MAINTAINABILITY OF EQUIPMENT –

Part 2: Maintainability requirements and studies
during the design and development phase



1 Scope
This part of IEC 60706 examines the maintainability requirements and related design and use
parameter, and discusses some activities necessary to achieve the required maintainability
characteristics and their relationship to planning of maintenance. It describes the general
approach in reaching these objectives and shows how maintainability characteristics should
be specified in a requirements document or contract.
It is not intended to be a complete guide on how to specify or to contract for maintainability.
Its purpose is to define the range of considerations when maintainability characteristics are
included as requirements for the development or the acquisition of an item.
The standard goes on to describe maintainability studies in the preliminary and detailed
design phases and their relationships to other maintainability and maintenance support tasks,
described in associated standards. Maintainability considerations in design reviews are also
included.
It is intended that customers acquiring items of equipment will find this standard useful in
assisting them to define their maintainability objectives and associated maintainability
programmes.
2 Normative references
The following referenced documents are indispensable for the application 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.
IEC 60050(191):1990, International Electrotechnical Vocabulary (IEV) – Chapter 191:
Dependability and quality of service
IEC 60300-3-1, Dependability management – Part 3-1: Application guide – Analysis
techniques for dependability – Guide on methodology
IEC 60300-3-3, Dependability management – Part 3-3: Application guide – Life cycle costing
IEC 60300-3-10:2001, Dependability management – Part 3-10: Application guide – Maintain-
ability
IEC 60300-3-11, Dependability management – Part 3-11: Application guide – Reliability
centred maintenance

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SIST EN 60706-2:2007
60706-2  IEC:2006 – 15 –
IEC 60300-3-12, Dependability management – Part 3-12: Application guide – Integrated
logistic support
IEC 60300-3-14, Dependability management – Part 3-14: Application guide – Maintenance
and maintenance support
IEC 60706-3, Guide on maintainability of equipment – Part 3: Sections Six and Seven –
1
Verification and collection, analysis and presentation of data
IEC 60706-5, Guide on maintainability of equipment – Part 5 – Section 4: Diagnostic testing
IEC 60812, Analysis techniques for system reliability – Procedure for failure mode and effects
analysis (FMEA)
IEC 61025, Fault tree analysis (FTA)
IEC 61160, Design review
IEC 61649, Goodness-of-fit tests, confidence intervals and lower confidence limits for Weibull
distributed data
3 Terms, definitions and acronyms
For the purposes of this document, the terms and definitions given in IEC 60050(191) apply,
together with the following:
3.1 Terms and definitions
3.1.1
maintainability (performance)
ability of an item under given conditions of use, to be retained in, or restored to, a state in
which it can perform a required function, when maintenance is performed under given
conditions and using stated procedures and resources
NOTE The term "maintainability" is also used as a measure of maintainability performance (see 191-13-01).
[IEV 191-02-07:1990]
3.1.2
maintainability
probability that a given maintenance action, for an item under given conditions of use, can be
carried out within a stated time interval, when the maintenance is performed under stated
conditions and using stated procedures and resources
NOTE The term "maintainability" is also used to denote the maintainability performance quantified by this
probability (see 191-02-07:1990).
[IEV 191-13-01:1990]
___________
1 A second edition is due to be published shortly under the revised title “Maintainability of equipment – Part 3:
Verification and collection, analysis and presentation of data”.

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SIST EN 60706-2:2007
60706-2  IEC:2006 – 17 –
3.1.3
maintenance
combination of all technical and administrative actions, including supervision actions, intended
to retain an item in, or restore it to, a state in which it can perform a required function
[IEV 191-07-01:1990]
3.1.4
maintenance concept
interrelationship between the maintenance echelons, the indenture levels and the levels of
maintenance to be applied for the maintenance of an item
3.1.5
maintenance policy
general approach to the provision of maintenance and maintenance support based on the
objectives and policies of owners, users and customers
3.2 Acronyms
BITE built-in test equipment
FMEA failure modes and effects analysis
FTA fault tree analysis
ILS integrated logistic support
LCC life cycle cost
LRU line replaceable unit
LSA logistic support analysis
MART mean active repair time
MTTR mean time to repair (or restoration or recovery)
RCM reliability centred maintenance
SSI software significant item
4 General approach
An important portion of the cost of using an item is the total resources spent on those tasks
necessary to retain an item in, or restore it to, a satisfactory condition. This total effort is
related to the number of these tasks, their complexity and duration.
The design of an item shall ensure three things, namely:
a) that it achieves the performance required of it;
b) that it is reliable;
c) that it is maintainable.
The second and third of these characteristics directly affect the maintenance effort which shall
be expended on an item in that the achieved reliability reflects the frequency of unscheduled
maintenance and the maintainability reflects the effort necessary to undertake all
maintenance.

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SIST EN 60706-2:2007
60706-2  IEC:2006 – 19 –
Therefore actions performed during the design of an item and intended to affect the failure
rate and the severity of the failures call mainly for reliability techniques, while those intended
to affect the preventive and corrective maintenance and the duration, cost and support
requirements of maintenance tasks call mainly for maintainability techniques.
An item that can be maintained easily and is supported by a competent and efficient
maintenance organization has a greater availability and a reduced life cycle cost than one that
does not have these attributes. The degree of effort that is put into achieving good
maintainability and an efficient support organization depends on the type of product and the
use to which it is put, and is based on operational, economic and safety factors.
During the design phase, components with wear out must be identified, and their life time be
determined, for example, by using Weibull analysis (see IEC 61649). The trade-off between
components with higher life time versus the cost of preventive or corrective maintenance
should be documented. In this way the system can be designed for minimum maintenance.
5 Principle of maintainability
This standard examines the maintainability and related design and use parameters and
discusses some of the activities necessary to achieve the required maintainability character-
istics and their relationship to the planning of maintenance.
Maintainability has a major impact on the cost of support and the availability of an equipment
and is concerned with characteristics of design, manufacture and installation which affect the
ability of an item to conform to specified requirements of use and of maintenance. This ability
is usually measured in both qualitative and quantitative terms.
NOTE The concepts described in this standard can be applied to a small product or to a major project and
therefore, as defined in IEC 60050(191):191-01-01:1990, “item” is used to denote any part, device, subsystem,
functional unit, equipment or system that can be individually considered.
The maintainability characteristics depend on the following:
a) the ability of the item to be retained in or restored to service (subject to the provision of
facilities for diagnosis and accessibility of parts, etc.), all conditions of
...