ISO 26262-1:2018

INTERNATIONAL ISO
STANDARD 26262-1
Second edition
2018-12
Road vehicles — Functional safety —
Part 1:
Vocabulary
Véhicules routiers — Sécurité fonctionnelle —
Partie 1: Vocabulaire
Reference number
©
ISO 2018
© ISO 2018
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ii © ISO 2018 – All rights reserved

Contents Page
Foreword .iv
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Abbreviated terms .28
Bibliography .33
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
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ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
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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
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URL: www .iso .org/iso/foreword .html.
This document was prepared by Technical Committee ISO/TC 22, Road vehicles Subcommittee, SC 32,
Electrical and electronic components and general system aspects.
This edition of ISO 26262 series of standards cancels and replaces the edition ISO 26262:2011 series of
standards, which has been technically revised and includes the following main changes:
— requirements for trucks, buses, trailers and semi-trailers;
— extension of the vocabulary;
— more detailed objectives;
— objective oriented confirmation measures;
— management of safety anomalies;
— references to cyber security;
— updated target values for hardware architecture metrics;
— guidance on model based development and software safety analysis;
— evaluation of hardware elements;
— additional guidance on dependent failure analysis;
— guidance on fault tolerance, safety-related special characteristics and software tools;
— guidance for semiconductors;
— requirements for motorcycles; and
— general restructuring of all parts for improved clarity.
iv © ISO 2018 – All rights reserved

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.
A list of all parts in the ISO 26262 series can be found on the ISO website.
Introduction
The ISO 26262 series of standards is the adaptation of IEC 61508 series of standards to address the
sector specific needs of electrical and/or electronic (E/E) systems within road vehicles.
This adaptation applies to all activities during the safety lifecycle of safety-related systems comprised
of electrical, electronic and software components.
Safety is one of the key issues in the development of road vehicles. Development and integration of
automotive functionalities strengthen the need for functional safety and the need to provide evidence
that functional safety objectives are satisfied.
With the trend of increasing technological complexity, software content and mechatronic
implementation, there are increasing risks from systematic failures and random hardware failures,
these being considered within the scope of functional safety. ISO 26262 series of standards includes
guidance to mitigate these risks by providing appropriate requirements and processes.
To achieve functional safety, the ISO 26262 series of standards:
a) provides a reference for the automotive safety lifecycle and supports the tailoring of the activities
to be performed during the lifecycle phases, i.e., development, production, operation, service and
decommissioning;
b) provides an automotive-specific risk-based approach to determine integrity levels [Automotive
Safety Integrity Levels (ASILs)];
c) uses ASILs to specify which of the requirements of ISO 26262 are applicable to avoid unreasonable
residual risk;
d) provides requirements for functional safety management, design, implementation, verification,
validation and confirmation measures; and
e) provides requirements for relations between customers and suppliers.
The ISO 26262 series of standards is concerned with functional safety of E/E systems that is achieved
through safety measures including safety mechanisms. It also provides a framework within which
safety-related systems based on other technologies (e.g. mechanical, hydraulic and pneumatic) can be
considered.
The achievement of functional safety is influenced by the development process (including such
activities as requirements specification, design, implementation, integration, verification, validation
and configuration), the production and service processes and the management processes.
Safety is intertwined with common function-oriented and quality-oriented activities and work
products. The ISO 26262 series of standards addresses the safety-related aspects of these activities and
work products.
Figure 1 shows the overall structure of the ISO 26262 series of standards. The ISO 26262 series of
standards is based upon a V-model as a reference process model for the different phases of product
development. Within the figure:
— the shaded “V”s represent the interconnection among ISO 26262-3, ISO 26262-4, ISO 26262-5,
ISO 26262-6 and ISO 26262-7;
— for motorcycles:
— ISO 26262-12:2018, Clause 8 supports ISO 26262-3;
— ISO 26262-12:2018, Clauses 9 and 10 support ISO 26262-4;
— the specific clauses are indicated in the following manner: “m-n”, where “m” represents the number
of the particular part and “n” indicates the number of the clause within that part.
vi © ISO 2018 – All rights reserved

EXAMPLE “2-6” represents ISO 26262-2:2018, Clause 6.
Figure 1 — Overview of the ISO 26262 series of standards
INTERNATIONAL STANDARD ISO 26262-1:2018(E)
Road vehicles — Functional safety —
Part 1:
Vocabulary
1 Scope
This document is intended to be applied to safety-related systems that include one or more electrical
and/or electronic (E/E) systems and that are installed in series production road vehicles, excluding
mopeds. This document does not address unique E/E systems in special vehicles such as E/E systems
designed for drivers with disabilities.
NOTE Other dedicated application-specific safety standards exist and can complement the ISO 26262 series
of standards or vice versa.
Systems and their components released for production, or systems and their components already under
development prior to the publication date of this document, are exempted from the scope of this edition.
This document addresses alterations to existing systems and their components released for production
prior to the publication of this document by tailoring the safety lifecycle depending on the alteration.
This document addresses integration of existing systems not developed according to this document and
systems developed according to this document by tailoring the safety lifecycle.
This document addresses possible hazards caused by malfunctioning behaviour of safety-related E/E
systems, including interaction of these systems. It does not address hazards related to electric shock,
fire, smoke, heat, radiation, toxicity, flammability, reactivity, corrosion, release of energy and similar
hazards, unless directly caused by malfunctioning behaviour of safety-related E/E systems.
This document describes a framework for functional safety to assist the development of safety-
related E/E systems. This framework is intended to be used to integrate functional safety activities
into a company-specific development framework. Some requirements have a clear technical focus to
implement functional safety into a product; others address the development process and can therefore
be seen as process requirements in order to demonstrate the capability of an organization with respect
to functional safety.
This document defines the vocabulary of terms used in the ISO 26262 series of standards.
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 26262 (all parts), Road vehicles — Functional safety
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 26262 (all parts) and the
following 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
architecture
representation of the structure of the item (3.84) or element (3.41) that allows identification of
building blocks, their boundaries and interfaces, and includes the allocation of requirements to these
building blocks
3.2
ASIL capability
capability of the item (3.84) or element (3.41) to meet assumed safety (3.132) requirements assigned
with a given ASIL (3.6)
Note 1 to entry: As a part of hardware safety requirements, achievement of the corresponding random hardware
target values for fault metrics (see ISO 26262-5:2018, Clauses 8 and 9) allocated to the element (3.41) is included,
if needed.
3.3
ASIL decomposition
apportioning of redundant safety (3.132) requirements to elements (3.41), with sufficient independence
(3.78), conducing to the same safety goal (3.139), with the objective of reducing the ASIL (3.6) of the
redundant safety (3.132) requirements that are allocated to the corresponding elements (3.41)
Note 1 to entry: ASIL decomposition is a basis for methods of ASIL (3.6) tailoring during the design process
(defined as requirements decomposition with respect to ASIL (3.6) tailoring in ISO 26262-9).
Note 2 to entry: ASIL decomposition does not apply to random hardware failure requirements per ISO 26262-9.
Note 3 to entry: Reducing the ASIL (3.6) of the redundant safety (3.132) requirements has some exclusions, e.g.
confirmation measures (3.23) remain at the level of the safety goal (3.139).
3.4
assessment
examination of whether a characteristic of an item (3.84) or element (3.41) achieves the ISO 26262
objectives
3.5
audit
examination of an implemented process with regard to the process objectives
3.6
automotive safety integrity level
ASIL
one of four levels to specify the item's (3.84) or element's (3.41) necessary ISO 26262 requirements and
safety measures (3.141) to apply for avoiding an unreasonable risk (3.176), with D representing the most
stringent and A the least stringent level
Note 1 to entry: QM (3.117) is not an ASIL.
3.7
availability
capability of a product to provide a stated function if demanded, under given conditions over its defined
lifetime
3.8
base failu
...