SIST EN ISO 20815:2019

Petroleum, petrochemical and natural gas industries - Production assurance and reliability management (ISO 20815:2018)

This document describes the concept of production assurance within the systems and operations
associated with exploration drilling, exploitation, processing and transport of petroleum, petrochemical
and natural gas resources. This document covers upstream (including subsea), midstream and
downstream facilities, petrochemical and associated activities. It focuses on production assurance of
oil and gas production, processing and associated activities and covers the analysis of reliability and
maintenance of the components. This includes a variety of business categories and associated systems/
equipment in the oil and gas value chain. Production assurance addresses not only hydrocarbon
production, but also associated activities such as drilling, pipeline installation and subsea intervention.
This document provides processes and activities, requirements and guidelines for systematic
management, effective planning, execution and use of production assurance and reliability technology.
This is to achieve cost-effective solutions over the life cycle of an asset development project structured
around the following main elements:
— production assurance management for optimum economy of the facility through all of its life cycle
phases, while also considering constraints arising from health, safety, environment, and quality;
— planning, execution and implementation of reliability technology;
— application of reliability and maintenance data;
— reliability-based technology development, design and operational improvement.
The IEC 60300-3 series addresses equipment reliability and maintenance performance in general.
This document designates 12 processes, of which seven are defined as core production assurance
processes and addressed in this document. The remaining five processes are denoted as interacting
processes and are outside the scope of this document. The interaction of the core production assurance
processes with these interacting processes, however, is within the scope of this document as the
information flow to and from these latter processes is required to ensure that production assurance
requirements can be fulfilled.
The only requirement mandated by this document is the establishment and execution of the production
assurance programme (PAP). It is important to reflect the PAP in the overall project management in the
project for which it applies.
This document recommends that the listed processes and activities be initiated only if they can be
considered to add value.

Erdöl-, petrochemische und Erdgasindustrie - Betriebsoptimierung und Zuverlässigkeitsmanagement (ISO 20815:2018)

Industries du pétrole, de la pétrochimie et du gaz naturel - Assurance de la production et management de la fiabilité (ISO 20815:2018)

Le présent document introduit le concept d'assurance production dans les systèmes et les opérations liés au forage, à l'exploitation, au traitement et au transport des ressources pétrolières, pétrochimiques et en gaz naturel. Le présent document couvre les installations et les activités amont (y compris sous-marines), intermédiaires et aval, la pétrochimie ainsi que les activités associées. Il est axé sur l'assurance production relative à la production du pétrole et du gaz, sur le traitement et les opérations associées et couvre l'analyse de la fiabilité et de la maintenance des composants. Cela comprend une variété de catégories d'activité et de systèmes/équipements associés au sein de la chaîne de valeur du gaz et du pétrole. L'assurance production concerne non seulement la production des hydrocarbures, mais également les activités associées telles que le forage, l'installation de conduites et les interventions sous-marines.
Le présent document fournit des processus et des activités, des exigences et des lignes directrices pour la gestion systématique, la planification, l'exécution et l'utilisation efficaces de l'assurance production et des techniques fiabilistes. Le but est d'obtenir des solutions rentables sur tout le cycle de vie d'un projet de développement d'une installation de production structurée autour des éléments principaux suivants:
—          gestion de l'assurance production pour une économie optimale de l'installation durant toutes les phases de son cycle de vie, tout en tenant compte des contraintes résultant de facteurs liés à la santé, à la sécurité, à l'environnement et à la qualité;
—          planification, exécution et mise en œuvre des techniques fiabilistes;
—          application des données de fiabilité et de maintenance;
—          amélioration du développement, de la conception et de l'exploitation de technologies basées sur la fiabilité.
La série IEC 60300-3 a trait à la fiabilité des équipements et à l'exécution de la maintenance.
Le présent document définit douze processus, dont sept sont définis comme des processus fondamentaux de l'assurance production et sont abordés dans le présent document. Les cinq processus restants sont appelés processus en interaction et ne relèvent pas du domaine d'application du présent document. L'interaction des processus fondamentaux de l'assurance production avec ces processus interactifs s'inscrit toutefois dans le domaine d'application du présent document car le flux d'informations à destination et en provenance de ces derniers processus est requis pour s'assurer que les exigences de l'assurance production peuvent être remplies.
La seule exigence spécifiée par le présent document concerne l'établissement et l'exécution du programme d'assurance production (PAP). Il est important que le PAP se reflète dans la gestion globale du projet auquel il s'applique.
Le présent document recommande de ne lancer les processus et activités qu'il énumère que s'ils peuvent apporter de la valeur ajoutée.

Petrokemična industrija ter industrija za predelavo nafte in zemeljskega plina - Optimizacija proizvodnje in upravljanje zanesljivosti (ISO 20815:2018)

Ta dokument opisuje koncept zagotavljanja proizvodnje v sistemih in operacijah, povezanih z raziskovalnim vrtanjem, izkoriščanjem, predelavo in prevozom nafte ter petrokemičnih virov in virov zemeljskega plina. Ta dokument zajema objekte geoloških raziskav in proizvodnje (vključno s podvodnimi), transporta, predelave in trženja nafte oziroma zemeljskega plina ter petrokemične in z njimi povezane dejavnosti. Osredotoča se na zagotavljanje proizvodnje nafte in plina, predelavo in s tem povezane dejavnosti ter zajema analizo zanesljivosti in vzdrževanja komponent. To vključuje različne poslovne kategorije in pripadajoče sisteme/opremo v vrednostni verigi nafte in zemeljskega plina. Zagotavljanje proizvodnje se ne nanaša samo na proizvodnjo ogljikovodikov, temveč tudi na povezane dejavnosti, kot so vrtanje, namestitev cevovodov in podvodni posegi. Ta dokument vsebuje postopke in dejavnosti, zahteve in smernice za sistematično upravljanje, učinkovito načrtovanje, izvajanje ter uporabo tehnologije za optimizacijo in zanesljivost proizvodnje. S tem se želi doseči stroškovno učinkovite rešitve v celotnem življenjskem ciklu projekta razvoja sredstev, oblikovanega na podlagi teh glavnih elementov:
– upravljanje optimizacije proizvodnje za optimalno ekonomičnost objekta skozi vse faze njegovega življenjskega cikla ob upoštevanju omejitev v zvezi z zdravjem, varnostjo, okoljem in kakovostjo;
– načrtovanje, izvajanje in uvajanje tehnologije zanesljivosti;
– uporaba podatkov o zanesljivosti in vzdrževanju;
– razvoj, projektiranje in izboljšanje delovanja na podlagi zanesljivosti.
Skupina standardov IEC 60300-3 obravnava zanesljivost in vzdrževanje opreme na splošno. Ta dokument opredeljuje 12 procesov, od katerih jih je sedem opredeljenih kot procesi optimizacije temeljne proizvodnje. Preostalih pet procesov je označenih kot medsebojno delujoči procesi in so zunaj področja uporabe tega dokumenta. Vzajemno delovanje procesov optimizacije temeljne proizvodnje s temi interakcijskimi procesi pa je zajeto v tem dokumentu, saj je za izpolnjevanje zahtev optimizacije proizvodnje potreben pretok informacij do teh procesov in iz njih.
Edina zahteva, določena v tem dokumentu, je vzpostavitev in izvajanje programa optimizacije proizvodnje (PAP). Pomembno je, da se program optimizacije proizvodnje odraža v celotnem vodenju projekta, za katerega se uporablja.
Ta dokument priporoča, da se navedeni procesi in aktivnosti začnejo izvajati le, če projektu lahko zagotovijo dodano vrednost.

General Information

• Status: Published
• Public Enquiry End Date: 30-Sep-2017
• Publication Date: 10-Dec-2018
• ICS: 03.100.01 - Company organization and management in general
• ICS: 75.020 - Extraction and processing of petroleum and natural gas
• Technical Committee: I13 - Imaginarni 13
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 06-Dec-2018
• Due Date: 10-Feb-2019
• Completion Date: 11-Dec-2018
• Ref Project: EN ISO 20815:2018 - Petroleum, petrochemical and natural gas industries - Production assurance and reliability management (ISO 20815:2018)

Relations

• Revised: SIST EN ISO 20815:2010 - Petroleum, petrochemical and natural gas industries - Production assurance and reliability management (ISO 20815:2008, Corrected version 2009-06-15)
• Effective Date: 17-Feb-2016
• Replaces: SIST EN ISO 20815:2010 - Petroleum, petrochemical and natural gas industries - Production assurance and reliability management (ISO 20815:2008, Corrected version 2009-06-15)
• Effective Date: 05-Dec-2018

Standards Content (Sample)

SLOVENSKI STANDARD
SIST EN ISO 20815:2019
01-februar-2019
1DGRPHãþD
SIST EN ISO 20815:2010
3HWURNHPLþQDLQGXVWULMDWHULQGXVWULMD]DSUHGHODYRQDIWHLQ]HPHOMVNHJDSOLQD
2SWLPL]DFLMDSURL]YRGQMHLQXSUDYOMDQMH]DQHVOMLYRVWL,62
Petroleum, petrochemical and natural gas industries - Production assurance and
reliability management (ISO 20815:2018)
Erdöl-, petrochemische und Erdgasindustrie - Betriebsoptimierung und
Zuverlässigkeitsmanagement (ISO 20815:2018)

Industries du pétrole, de la pétrochimie et du gaz naturel - Assurance de la production et

management de la fiabilité (ISO 20815:2018)
Ta slovenski standard je istoveten z: EN ISO 20815:2018
ICS:
03.100.01 Organizacija in vodenje Company organization and
podjetja na splošno management in general
75.020 Pridobivanje in predelava Extraction and processing of
nafte in zemeljskega plina petroleum and natural gas
SIST EN ISO 20815:2019 en,fr,de

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN ISO 20815:2019
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SIST EN ISO 20815:2019
EN ISO 20815
EUROPEAN STANDARD
NORME EUROPÉENNE
November 2018
EUROPÄISCHE NORM
ICS 75.180.01; 75.200 Supersedes EN ISO 20815:2010
English Version
Petroleum, petrochemical and natural gas industries -
Production assurance and reliability management (ISO
20815:2018)

Industries du pétrole, de la pétrochimie et du gaz Erdöl-, petrochemische und Erdgasindustrie -

naturel - Assurance de la production et management de Betriebsoptimierung und Zuverlässigkeitsmanagement

la fiabilité (ISO 20815:2018) (ISO 20815:2018)
This European Standard was approved by CEN on 7 October 2018.

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.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,

Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,

Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,

Turkey and 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

© 2018 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 20815:2018 E

worldwide for CEN national Members.
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SIST EN ISO 20815:2019
EN ISO 20815:2018 (E)
Contents Page

European foreword ....................................................................................................................................................... 3

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SIST EN ISO 20815:2019
EN ISO 20815:2018 (E)
European foreword

This document (EN ISO 20815:2018) has been prepared by Technical Committee ISO/TC 67 "Materials,

equipment and offshore structures for petroleum, petrochemical and natural gas industries" in

collaboration with Technical Committee CEN/TC 12 “Materials, equipment and offshore structures for

petroleum, petrochemical and natural gas industries” the secretariat of which is held by NEN.

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 May 2019, and conflicting national standards shall be

withdrawn at the latest by May 2019.

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.

This document supersedes EN ISO 20815:2010.

According to the CEN-CENELEC Internal Regulations, the national standards organizations of the

following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,

Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia,

France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,

Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,

Turkey and the United Kingdom.
Endorsement notice

The text of ISO 20815:2018 has been approved by CEN as EN ISO 20815:2018 without any modification.

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SIST EN ISO 20815:2019
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SIST EN ISO 20815:2019
INTERNATIONAL ISO
STANDARD 20815
Second edition
2018-10
Petroleum, petrochemical and
natural gas industries — Production
assurance and reliability management
Industries du pétrole, de la pétrochimie et du gaz naturel —
Assurance de la production et management de la fiabilité
Reference number
ISO 20815:2018(E)
ISO 2018
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SIST EN ISO 20815:2019
ISO 20815:2018(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2018

All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may

be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting

on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address

below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Fax: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii © ISO 2018 – All rights reserved
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SIST EN ISO 20815:2019
ISO 20815:2018(E)
Contents Page

Foreword ........................................................................................................................................................................................................................................iv

Introduction ..................................................................................................................................................................................................................................v

1 Scope ................................................................................................................................................................................................................................. 1

2 Normative references ...................................................................................................................................................................................... 1

3 Terms, definitions and abbreviated terms ................................................................................................................................ 2

3.1 Terms and definitions ....................................................................................................................................................................... 2

3.2 Abbreviations ........................................................................................................................................................................................15

4 Production assurance and decision support ........................................................................................................................17

4.1 Users of this document .................................................................................................................................................................17

4.2 Framework conditions ..................................................................................................................................................................17

4.3 Optimization process ......................................................................................................................................................................19

4.4 Production assurance programme .....................................................................................................................................21

4.4.1 Objectives ............................................................................................................................................................................21

4.4.2 Project risk categorization ...................................................................................................................................22

4.4.3 Programme activities ................................................................................................................................................23

4.5 Alternative standards .....................................................................................................................................................................25

5 Production assurance processes and activities.................................................................................................................26

Annex A (informative) Contents of production assurance programme (PAP) .......................................................28

Annex B (informative) Core production assurance processes and activities ..........................................................30

Annex C (informative) Interacting production assurance processes and activities .........................................39

Annex D (informative) Production performance analyses .........................................................................................................43

Annex E (informative) Reliability and production performance data ............................................................................50

Annex F (informative) Performance objectives and requirements ...................................................................................52

Annex G (informative) Performance measures for production availability .............................................................56

Annex H (informative) Relationship to major accidents ..............................................................................................................69

Annex I (informative) Outline of techniques .............................................................................................................................................71

Bibliography .............................................................................................................................................................................................................................96

© ISO 2018 – All rights reserved iii
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SIST EN ISO 20815:2019
ISO 20815:2018(E)
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.

The procedures used to develop this document and those intended for its further maintenance are

described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the

different types of ISO documents should be noted. This document was drafted in accordance with the

editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/directives).

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. Details of

any patent rights identified during the development of the document will be in the Introduction and/or

on the ISO list of patent declarations received (see www .iso .org/patents).

Any trade name used in this document is information given for the convenience of users and does not

constitute an endorsement.

For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and

expressions related to conformity assessment, as well as information about ISO's adherence to the

World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see www .iso

.org/iso/foreword .html.

This document was prepared by Technical Committee ISO/TC 67, Materials, equipment and offshore

structures for petroleum, petrochemical and natural gas industries.

This second edition cancels and replaces the first edition (ISO 20815:2008), which has been technically

revised. The main changes compared to the previous edition are as follows:
— Clause 3: several new terms, definitions and abbreviations;
— Clause 4: new 4.1 and new Figure 2;
— Annexes A, B, C and E: minor changes;
— Annex D: various new text and new figures;
— Annex F: new text in Clause F.3, new Clause F.4, and new figure;
— Annex G and H: some changes in Clauses G.2, G.3, H.1 and H.2;

— Annex I: various changes in Clauses I.7 to I.10, I.18 to I.22, and new Clauses I.23 to I.26.

Any feedback or questions on this document should be directed to the user’s national standards body. A

complete listing of these bodies can be found at www .iso .org/members .html.
iv © ISO 2018 – All rights reserved
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SIST EN ISO 20815:2019
ISO 20815:2018(E)
Introduction

The petroleum, petrochemical and natural gas industries involve large capital investment costs as well

as operational expenditures. The profitability of these industries is dependent upon the reliability,

availability and maintainability of the systems and components that are used. Therefore, for optimal

production availability in the oil and gas business, a standardized, integrated reliability approach is

required.

The concept of production assurance, introduced in this document, enables a common understanding

with respect to use of reliability technology in the various life cycle phases and covers the activities

implemented to achieve and maintain a performance level that is at its optimum in terms of the overall

economy and, at the same time, consistent with applicable regulatory and framework conditions.

Annexes A to I are for information only.
© ISO 2018 – All rights reserved v
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SIST EN ISO 20815:2019
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SIST EN ISO 20815:2019
INTERNATIONAL STANDARD ISO 20815:2018(E)
Petroleum, petrochemical and natural gas industries —
Production assurance and reliability management

IMPORTANT — The electronic file of this document contains colours which are considered to be

useful for the correct understanding of the document. Users should therefore consider printing

this document using a colour printer.
1 Scope

This document describes the concept of production assurance within the systems and operations

associated with exploration drilling, exploitation, processing and transport of petroleum, petrochemical

and natural gas resources. This document covers upstream (including subsea), midstream and

downstream facilities, petrochemical and associated activities. It focuses on production assurance of

oil and gas production, processing and associated activities and covers the analysis of reliability and

maintenance of the components. This includes a variety of business categories and associated systems/

equipment in the oil and gas value chain. Production assurance addresses not only hydrocarbon

production, but also associated activities such as drilling, pipeline installation and subsea intervention.

This document provides processes and activities, requirements and guidelines for systematic

management, effective planning, execution and use of production assurance and reliability technology.

This is to achieve cost-effective solutions over the life cycle of an asset development project structured

around the following main elements:

— production assurance management for optimum economy of the facility through all of its life cycle

phases, while also considering constraints arising from health, safety, environment, and quality;

— planning, execution and implementation of reliability technology;
— application of reliability and maintenance data;
— reliability-based technology development, design and operational improvement.

The IEC 60300-3 series addresses equipment reliability and maintenance performance in general.

This document designates 12 processes, of which seven are defined as core production assurance

processes and addressed in this document. The remaining five processes are denoted as interacting

processes and are outside the scope of this document. The interaction of the core production assurance

processes with these interacting processes, however, is within the scope of this document as the

information flow to and from these latter processes is required to ensure that production assurance

requirements can be fulfilled.

The only requirement mandated by this document is the establishment and execution of the production

assurance programme (PAP). It is important to reflect the PAP in the overall project management in the

project for which it applies.

This document recommends that the listed processes and activities be initiated only if they can be

considered to add value.
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.

© ISO 2018 – All rights reserved 1
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SIST EN ISO 20815:2019
ISO 20815:2018(E)

ISO 14224:2016, Petroleum, petrochemical and natural gas industries — Collection and exchange of

reliability and maintenance data for equipment
3 Terms, definitions and abbreviated terms
3.1 Terms and definitions
For the purposes of this document, the following terms and definitions apply.

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

— ISO Online browsing platform: available at https: //www .iso .org/obp
— IEC Electropedia: available at http: //www .electropedia .org/
3.1.1
active repair time
effective time to achieve repair of an item

Note 1 to entry: The expectation of the effective time to repair is called MART (mean active repair time).

Note 2 to entry: ISO 14224:2016 distinguishes between the terms mean active repair time (MART), mean time to

repair (MTTR), mean time to restoration (MTTRes), and mean overall repairing time (MRT). See ISO 14224:2016,

3.59, 3.63, 3.64 and 3.61 for further details.

Note 3 to entry: The mean active repair time (MART) is defined as “expected active repair time” in ISO/TR

12489:2013, 3.1.34. See also ISO/TR 12489:2013, Figures 5 and 6.
[SOURCE: ISO 14224:2016, 3.2, modified — Notes 1 to 2 to entry have been added.]
3.1.2
availability
ability to be in a state to perform as required

Note 1 to entry: For a binary item, the measure of the availability is the probability to be in up state (i.e. in a state

belonging to the up state class), see 3.1.59.

Note 2 to entry: In 3.1.4, the figure shows the system is available at time t and unavailable at time t .

1 2

Note 3 to entry: See ISO 14224:2016, Annex C for a more detailed description and interpretation of availability.

Note 4 to entry: Technical or operational availability (see ISO 14224:2016, C.2.3.2 and Table E.3) or system

availability can be used as derived performance measures. Case specific definition of system availability is

needed to reflect the system being addressed.
Note 5 to entry: Further terms are given in ISO/TR 12489:2013.
Note 6 to entry: See Figure G.1 for further information.

[SOURCE: IEC 60050-192:2015, 192-01-23, modified — Notes 1 to 6 to entry have been added.]

3.1.3
barrier

functional grouping of safeguards or controls selected to prevent a major accident or limit the

consequences
[SOURCE: ISO 17776:2016, 3.1.1]
3.1.4
binary item
item with two classes of states
Note 1 to entry: The two classes can be ‘up state’ and ‘down state’.
2 © ISO 2018 – All rights reserved
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SIST EN ISO 20815:2019
ISO 20815:2018(E)

EXAMPLE 1 A usual item with an up state (3.1.59) and a down state (3.1.10) is a binary item. Components A

and B in the figure below are binary items.

EXAMPLE 2 A system made up of two redundant binary items, A and B, has four states: S (both A and B in

up state), S (A in up state and B in down state), S (A in down state and B in up state), S (both A and B in down

2 3 4

state). If the system is able to operate as required in states S , S and S and not able in state S , it is a binary item

1 2 3 4

with the up state class {S , S , S } and the down class {S }. This is illustrated in the Figure showing availability

1 2 3 4
behaviour of an 1oo2 system.
3.1.5
common cause failure

failures of multiple items, which would otherwise be considered independent of one another, resulting

from a single cause

Note 1 to entry: See also Notes to entry for common cause failures in ISO 14224:2016, 3.5.

[SOURCE: IEC 60050-192:2015, 192-03-18, modified — Note 1 to entry has been added.]

3.1.6
condition monitoring
obtaining information about physical state or operational parameters

Note 1 to entry: Condition monitoring is used to determine when preventive maintenance may be required.

Note 2 to entry: Condition monitoring may be conducted automatically during operation or at planned intervals.

Note 3 to entry: Condition monitoring is part of condition-based maintenance. See also ISO 14224:2016, Figure 6.

[SOURCE: IEC 60050-192:2015, 192-06-28, modified — Note 3 to entry has been added.]

3.1.7
corrective maintenance
maintenance carried out after fault detection to effect restoration

Note 1 to entry: See also ISO/TR 12489:2013, Figures 5 and 6, which illustrate terms used for quantifying

corrective maintenance.
© ISO 2018 – All rights reserved 3
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SIST EN ISO 20815:2019
ISO 20815:2018(E)

[SOURCE: IEC 60050-192:2015, 192-06-06, modified — Note 1 to entry has been added.]

3.1.8
deliverability

ratio of deliveries to planned deliveries over a specified period of time, when the effect of compensating

elements, such as substitution from other producers and downstream buffer storage, is included

Note 1 to entry: See Figure G.1 for further information.
3.1.9
design life
planned usage time for the total system

Note 1 to entry: to entry It is important not to confuse design life with the ‘mean time to failure’ (MTTF), which

is comprised of several items that might be allowed to fail within the design life of the system as long as repair or

replacement is feasible.
3.1.10
down state
unavailable state
internally disabled state
internal disabled state

state of being unable to perform as required, due to internal fault, or preventive

maintenance

Note 1 to entry: This concept is related to a binary item (3.1.4), which can have several down states forming the

down state class of the item. All the states in the down state class are considered to be equivalent with regard to

the unavailability of the considered item.
Note 2 to entry: See also Notes to entry for down state in ISO 14224:2016, 3.15.

EXAMPLE In the figure in 3.1.4, the down state class of the system S comprises only one state {S } and the

system S is in down state at time t .

[SOURCE: IEC 60050-192:2015, 192-02-20, modified — Notes 1 and 2 have been added.]

3.1.11
down time
time interval during which an item is in a down state

Note 1 to entry: The down time includes all the delays between the item failure and the restoration of its service.

Down time can be either planned or unplanned (see ISO 14224:2016, Table 4).

Note 2 to entry: Down time can be equipment down time (see Figure 4 and Table 4 in ISO 14224:2016), production

down time (see Figures I.1 and I.2) or down time for other operations (e.g. drilling). It is important to distinguish

between the equipment down time itself and the down time of the plant to which the equipment belongs.

[SOURCE: IEC 60050-192:2015, 192-02-21, modified — Notes 1 and 2 have been added.]

3.1.12
downstream

business category most commonly used in the petroleum industry to describe post-production

processes
Note 1 to entry: See ISO 14224:2016, A.1.4 for further details.
[SOURCE: ISO 14224:2016, 3.17]
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3.1.13
failure
loss of ability to perform as required

Note 1 to entry: A failure of an item is an event that results in a fault (i.e. a state) of that item (see 3.1.18). This is

illustrated in the figure in 3.1.50 for a binary system S comprising two redundant components A and B.

[SOURCE: IEC 60050-192:2015, 192-03-01, modified — Note 1 to entry has been added.]

3.1.14
failure cause
root cause
set of circumstances that leads to failure

Note 1 to entry: A failure cause can originate during specification, design, manufacture, installation, operation or

maintenance of an item.

Note 2 to entry: See also ISO 14224:2016, B.2.3 and Table B.3, which define failure causes for all equipment

classes.

[SOURCE: IEC 60050-192:2015, 192-03-11, modified — Note 2 to entry has been added.]

3.1.15
failure data
data characterizing the occurrence of a failure event
Note 1 to entry: See also ISO 14224:2016, Table 6.
[SOURCE: ISO 14224:2016, 3.25]
3.1.16
failure mode
manner in which failure occurs

Note 1 to entry: See also the tables in ISO 14224:2016, B.2.6, on the relevant failure modes, which define failure

modes to be used for each equipment class.

[SOURCE: IEC 60050-192:2015, 192-03-17, modified — Note 1 to entry has been added.]

3.1.17
failure rate

conditional probability per unit of time that the item fails between t and t + dt, provided that it has been

working over [0, t]
[SOURCE: ISO/TR 12489:2013, modified — Notes 1 to 4 to entry have been added.]

Note 1 to entry: See ISO 14224:2016, C.3 for further explanation of the failure rate.

Note 2 to entry: This definition applies for the first failure of binary items (3.1.4).

Note 3 to entry: Under the assumptions that the failure rate is constant and that the item is as good as new after

repairs the failure rate can be estimated as the number of failures relative to the corresponding accumulated up

time divided by this accumulated up time. In this case this is the reciprocal of MTTF (3.1.34). In some cases, time

can be replaced by units of use.

Note 4 to entry: The estimation of the failure rate can be based on operating time or calendar time.

3.1.18
fault
inability to perform as required, due to an internal state

Note 1 to entry: A fault of an item results from a failure, either of the item itself, or from a deficiency in an earlier

stage of the life cycle, such as specification, design, manufacture or maintenance. See latent fault (ISO 14224:2016,

3.44). The down states of items A, B and S in the figure in 3.1.46 are examples of faults.

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Note 2 to entry: An item made of several sub-items (e.g. a system) which continues to perform as required in

presence of faults of one or several sub-items is called fault tolerant.
Note 3 to entry: See also ISO/TR 12489:2013, 3.2.2.

[SOURCE: IEC 60050-192:2015, 192-04-01, modified — Note 2 to entry has been added.]

3.1.19
fault tolerance

attribute of an item that makes it able to perform a required function in the presence of certain given

sub-item faults
3.1.20
human error
discrepancy between the human action taken or omitted and that intended
EXAMPLE Performing an incorrect action; omitting a required action.
[81]

Note 1 to entry: Discrepancy with intention is considered essential in determining human error; see Reference .

Note 2 to entry: The term “human error” is often attributed in hindsight to a human decision, action or inaction

considered to be an initiator or contributory cause of a negative outcome such as loss or harm.

Note 3 to entry: In human reliability assessment, human error is defined as any member of a set of human actions

or activities that exceeds some limit of acceptability, this being an out of tolerance action or failure to act where

[78]
the limits of performance are defined by the system (see Reference ).
Note 4 to entry: See also IEC 62508:2010 for further details.
Note 5 to
...