ISO/TR 5340:2023

Motorcycles - Consideration for use cases of ISO 26262-12 MSIL classification

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 motorcycles. This document does not address unique E/E systems in special vehicles such as E/E systems designed for drivers with disabilities. NOTE The series production motorcycle is the vehicle that is intended to be used for public roads and is not a prototype. This document covers HARA for one or more E/E systems installed in motorcycles. The approach of HARA defined in ISO 26262-12:2018, Clause 8 is applied to them in a motorcycle environment. The intended user of this document is a functional-safety analyst complying with requirements in ISO 26262-12:2018. Therefore, this document does not intend to provide further necessary knowledge or guidelines in related fields including, but not limited to, item-specific knowledge, user and road profiling, medicine, statistics, accident research and human factors. Instead, it is intended to be related to the field of functional safety with the focus on the HARA examples only. It is the responsibility of the functional-safety analyst to achieve detailed knowledge about the item under investigation and the target application environment. In this document, the values shown are for reference only. Any new HARA can use the latest relevant data and analyses. The values shown in this document were derived based on some, but not all segments of information expected within an item description, and thus are not considered as an item definition. The ISO 26262 series requires that a HARA be based on a specific item definition. This document is not to be constructed to suggest that conducting a HARA without a specific item definition is acceptable. The scope of the ISO 26262 series is limited to functional safety which is one aspect of the overall system safety assessment in safety risk management. As for any risk assessment method, the methods mentioned in this document have inherent limitations. The HARA describes a simplified model of the real world, which is neither complete nor fully accurate. Although each assessment is based on available or applicable data as well as on expert judgment, the interpretation of such data can vary among analyses. For these reasons, the user of this document can bear in mind these limitations and judge the applicability of this document in any particular case.

Motocycles — Considération des cas d'usages de l'ISO 26262-12 Classification MSIL

General Information

• Status: Published
• Publication Date: 29-May-2023
• ICS: 43.140 - Motorcycles and mopeds
• Technical Committee: ISO/TC 22/SC 38 - Motorcycles and mopeds
• Drafting Committee: ISO/TC 22/SC 38 - Motorcycles and mopeds
• Current Stage: 6060 - International Standard published
• Start Date: 30-May-2023
• Due Date: 11-May-2023
• Completion Date: 30-May-2023

Overview

ISO/TR 5340:2023 - "Motorcycles - Consideration for use cases of ISO 26262-12 MSIL classification" is a technical report from ISO that provides motorcycle‑specific examples and guidance for performing Hazard Analysis and Risk Assessment (HARA) in accordance with ISO 26262-12:2018. It is intended for series production motorcycles that include one or more electrical/electronic (E/E) systems. The document collects illustrative HARA cases, explains motorcycle‑specific considerations for Motorcycle Safety Integrity Level (MSIL) classification, and shows how MSIL aligns with automotive ASIL concepts while accommodating motorcycle dynamics and industry practices.

Key topics and requirements

• Scope and applicability
  • Applies to safety‑related E/E systems installed in series production motorcycles (not mopeds or special‑purpose vehicles for drivers with disabilities).
  • Focuses exclusively on functional safety aspects covered by ISO 26262‑12.
• HARA process adapted for motorcycles
  • Uses the ISO 26262‑12:2018 Clause 8 approach to identify hazards, assess risk, determine safety goals, and assign MSIL.
  • Emphasizes motorcycle‑unique hazards (e.g., falls, lean angle effects, single‑rider controllability).
• Hazard identification techniques
  • Recommends item‑level methods such as FMEA and HAZOP supported by brainstorming, checklists, field data and quality history.
  • Lists example failure modes to guide identification (function active when expected off, late output, wrong direction, etc.).
• Risk assessment criteria
  • MSIL is derived from Severity (S), Exposure (E) and Controllability (C) comparable to ASIL methodology, but tailored to motorcycle rider interaction and external risk reduction measures.
• Limitations and responsibilities
  • The report provides reference values and example cases only; a proper HARA must be based on a specific item definition and up‑to‑date data.
  • It does not replace domain knowledge in user profiling, accident research, medicine or human factors.

Practical applications and users

• Primary users
  • Functional‑safety analysts, systems engineers and designers working on motorcycle E/E systems who are implementing ISO 26262‑12.
• Practical uses
  • Use as a reference for motorcycle‑specific HARA scenarios and MSIL classification examples.
  • Support development of safety goals and allocation of risk reduction between E/E systems and external measures (rider training, PPE, infrastructure).
  • Complement internal safety processes where motorcycle dynamics and controllability differ from passenger cars.
• Benefits
  • Faster onboarding for teams new to motorcycle functional safety.
  • Concrete example workflows to illustrate HARA techniques (FMEA, HAZOP) in a motorcycle context.

Related standards

• ISO 26262‑12:2018 - Motorcycle sector‑specific guidance for ISO 26262.
• ISO 26262‑1 - Functional safety vocabulary and foundational concepts referenced by ISO/TR 5340.

Keywords: ISO/TR 5340, ISO 26262-12, MSIL, HARA, motorcycle functional safety, E/E systems, hazard analysis, risk assessment.

Standards Content (Sample)

TECHNICAL ISO/TR
REPORT 5340
First edition
2023-05
Motorcycles — Consideration for
use cases of ISO 26262-12 MSIL
classification
Motocycles — Considération des cas d'usages de l'ISO 26262-12
Classification MSIL
Reference number
© ISO 2023
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
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or ISO’s member body in the country of the requester.
ISO copyright office
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Phone: [phone]
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Website: www.iso.org
Published in Switzerland
ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative reference .1
3 Terms and definitions . 1
4 General topics for MSIL classification . 2
5 Use case of hazard analysis and risk assessment . 2
5.1 Overview . 2
5.1.1 Item definition . 2
5.1.2 Hazard identification . 2
5.1.3 Risk assessment . 4
5.2 Examples of HARA . 4
5.2.1 General . 4
5.2.2 Example for HARA procedure . 4
5.2.3 Safety goal determination. 5
5.2.4 Examples of HARA method . 5
5.2.5 HARA example 1 . 6
5.2.6 HARA example 2 . 8
5.2.7 HARA example 3 . 10
Bibliography .16
iii
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 22, Road vehicles, Subcommittee SC 38,
Motorcycles and mopeds.
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
Introduction
0.1  General
The ISO 26262 series 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. The ISO 26262 series does not address unique E/E systems in special vehicles such
as E/E systems designed for drivers with disabilities.
ISO 26262-12:2018 is the standard to address the sector-specific needs of E/E systems within series
production motorcycles. The motorcycle industry recognizes the need to use appropriate safety-related
techniques to avoid unreasonable risk resulting from random or systematic faults of E/E systems.
Motorcycle safety integrity level (MSIL) is the output of hazard analysis and risk assessment (HARA).
This is then apportioned between the risk-reduction mechanisms and measures assigned to E/E
systems using automotive safety integrity level (ASIL) and the risk reduction taken care of by external
measures and/or other technologies. Specifically in the motorcycle industry, a greater proportion of the
overall risk reduction is generally apportioned to external measures (for example, riding rules, training/
qualification of riders, personal protective equipment, e.g. helmets and infrastructure features).
The worldwide established level of technology (“state-of-the-art”) in the motorcycle industry suggests
that ASIL requirements are not appropriate for motorcycles. This is addressed through the alignment
between MSIL and ASIL. It is acknowledged that product development processes and technical solutions
within the motorcycle industry are inhomogeneous with those of the automobile industry; therefore,
the difference between MSIL and ASIL has been made to accommodate worldwide capability.
0.2  Objectives
Publicly-available research documents and references relating to the functional safety of motorcycles
are fewer in number than those for passenger cars. The purpose of this document is to contribute to the
functional safety of motorcycles by internationally collecting and providing examples for motorcycle
HARA. This document provides an overview of the principles behind HARA using simplified examples
to the concepts.
A prerequisite for HARA is the item definition, which is not the subject of this document. It also does not
cover the safety goals of the item. This document takes examples of some items on motorcycles, but is
also not exhaustive in terms of their function.
This document presents examples of potential accident scenarios and risk assessments, from the
behaviour of an item when it fails and the hazard at vehicle level to its potential accident scenarios.
Several methods have been published for each of these, and the aim is to provide a side-by-side
comparison to assist in the implementation of HARA.
0.3  Points to note
In using this document, please note the following.
The hazard analysis results and MSIL described in this document is just a collection and does not specify
the MSIL of a specific item. Although some examples are given in this document, they are the result of
several approaches and do not specify the MSIL for a particular item. The same applies even if only one
example is given for an item. Also, the information presented in this document is neither exhaustive nor
complete. However, introducing some cases (i.e. analytical approaches and results) will help shape the
image for applying the ISO 26262 series.
This document has taken as faithfully as possible the descriptions from published documents. Although
there are formatting differences from the original text for the purpose of side-by-side comparison,
severity(S), exposure(E), controllability(C) and MSIL described have not been altered or harmonised
in any way. The information contained in this document is only part of the published material, and it is
recommended to consult the original when referring to it in implementation. The use of these methods
is neither mandatory nor recommended and is to be used at the user's own responsibility.
v
TECHNICAL REPORT ISO/TR 5340:2023(E)
Motorcycles — Consideration for use cases of ISO 26262-12
MSIL classification
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 motorcycles. This document
does not address unique E/E systems in special vehicles such as E/E systems designed for drivers with
disabilities.
NOTE The series production motorcycle is the vehicle that is intended to be used for public roads and is not a
prototype.
This document covers HARA for one or more E/E systems installed in motorcycles. The approach of
HARA defined in ISO 26262-12:2018, Clause 8 is applied to them in a motorcycle environment.
The intended user of this document is a functional-safety analyst complying with requirements in
ISO 26262-12:2018. Therefore, this document does not intend to provide further necessary knowledge
or guidelines in related fields including, but not limited to, item-specific knowledge, user and road
profiling, medicine, statistics, accident research and human factors. Instead, it is intended to be related
to the field of functional safety with the focus on the HARA examples only. It is the responsibility of
the functional-safety analyst to achieve detailed knowledge about the item under investigation and the
target application environment.
In this document, the values shown are for reference only. Any new HARA can use the latest relevant
data and analyses. The values shown in this document were derived based on some, but not all segments
of information expected within an item description, and thus are not considered as an item definition.
The ISO 26262 series requires that a HARA be based on a specific item definition. This document is not
to be constructed to suggest that conducting a HARA without a specific item definition is acceptable.
The scope of the ISO 26262 series is limited to functional safety which is one aspect of the overall
system safety assessment in safety risk management.
As for any risk assessment method, the methods mentioned in this document have inherent limitations.
The HARA describes a simplified model of the real world, which is neither complete nor fully accurate.
Although each assessment is based on available or applicable data as well as on expert judgment, the
interpretation of such data can vary among analyses. For these reasons, the user of this document can
bear in mind these limitations and judge the applicability of this document in any particular case.
2 Normative reference
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 26262-1, Road vehicles — Functional safety — Part 1: Vocabulary
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 26262-1 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/
4 General topics for MSIL classification
Hazard analysis, risk assessment and MSIL determination are used to determine the safety goals for the
item. For this, the item is evaluated with regard to its potential hazardous events. Safety goals and their
assigned MSIL are determined by a systematic evaluation of hazardous events. The MSIL is determined
by considering severity, probability of exposure and controllability. It is based on the item’s functional
behaviour; therefore, the detailed design of the item does not need to be known.
The dynamic behaviour of motorcycles differs greatly from that of other vehicles within the scope of
the ISO 26262 series, and that controllability of motorcycle specific hazardous events could place more
emphasis on the rider. It is recognised that the method of performing risk assessment requires to best
suit motorcycle specific hazardous events.
ISO 26262-12:2018, Annex B gives a general explanation of the hazard analysis and risk assessment.
5 Use case of hazard analysis and risk assessment
5.1 Overview
This clause presents examples of HARA in motorcycles.
HARA is a method to identify and categorize hazardous events of items and to specify safety goals and
MSILs related to the prevention or mitigation of the associated hazards in order to avoid unreasonable
risk.
The method of performing a HARA is the same as that of a passenger car, but different hazardous
events (such as falls down) can be identified depending on the situation peculiar to a motorcycle
and the difference in controllability. Evaluation of severity and exposure to driver and others differs
significantly from the case of passenger cars.
The case presented below is an example of analysing a scenario in a situation peculiar to motorcycles.
These are just a few of the situations that motorcycles encounter, and each item can have other serious
hazards. Also, the MSIL shown in the case is just the result of the case study and does not specify the
MSIL of the item in general.
Safety goals are top-level safety requirements for the item. Safety goals are not expressed in terms
of technological solutions, but in terms of functional objectives. This document does not mention the
items of functional objectives and safety goals.
5.1.1 Item definition
HARA is based on the item definition. The item without internal safety mechanisms is evaluated during
the hazard analysis and risk assessment, i.e. safety mechanisms intended to be implemented or that
have already been implemented in predecessor items are not considered in HARA.
5.1.2 Hazard identification
The purpose of hazard identification is to identify the potential source of harm caused by the
malfunctioning behaviour of the item.
Hazards caused by malfunctioning behaviour of the item are defined at the vehicle level.
The hazards are determined systematically based on the possible malfunctioning behaviour of the
item. Failure mode and effects analysis (FMEA) approaches and hazard and operability (HAZOP) are
suitable to support hazard identification at the item level. These can be supported by brainstorming,
checklists, quality history, and field studies. One example to identify a possible malfunction behaviour
with the HAZOP method can be to ask what can happen to the rider or other person if:
— the function is active when it is expected to be deactivated;
— the function is not active when it is expected to be activated;
— the output of the function is unintendedly too high;
— the output of the function is unintendedly too low;
— the output of the function came too late;
— the output of the function is changing too fast;
— the output of the function is in the wrong direction;
— the output of the function is alternating.
The identified malfunction behaviour that can cause harm to the rider or other person can be
documented as relevant malfunction with their consequences.
The relevant situations can be identified by analysing the expected usage and the expected misuse
of the motorcycle. The relevant situations can differ due to the design (e.g. superbike, enduro) or
3 3
performance (e.g. 125 cm /10 kW, 1 000 cm /150 kW) of the analysed motorcycle. Be aware of the
specific behaviour of a motorcycle (e.g. lean angle, separated front and rear brake), special manoeuvres
(e.g. wheelie, stoppie) and misuses (e.g. towing other vehicle, overloaded luggage in the top case).
One approach to identify all relevant situation is to build-up a list with possible parameters raised from,
for example:
Driving operation:
— driving speed;
— lean angle; and
— braking.
Road type:
— location (e.g. motorway, urban, crossing road); and
— road surface condition (e.g. dry, wet, ice).
Situations:
— overtaking;
— parking;
— wheelie;
— crash.
Be aware that a combination of parameters can change the consequences, because it can lead to an
inappropriate lowering of the MSIL.
The relevant situations where the identified malfunction can cause harm the rider or other person are
the hazardous events for the risk assessment. The consequences of hazardous events are identified.
EXAMPLE An unintended too-high torque output of the engine on a dry country road in a curve with large
lean angle can lead to leaving the road lane and to a collision with obstacles.
For a detailed description of the approach, refer to the ISO 26262-3:2018, 6.4.2 and ISO 26262-12:2018,
8.4.2.
5.1.3 Risk assessment
Risk assessment is a series of classifications of potential harms caused by hazards in terms of severity,
probability of exposure, or controllability.
The severity of the potential harm is estimated based on a defined rationale for each hazardous event.
The severity is assigned to one of the severity classes: S0, S1, S2 or S3.
The probability of exposure of each operational situation is estimated based on a defined rationale for
each hazardous event. The probability of exposure is assigned to one of the probability classes: E0, E1,
E2, E3 or E4.
The controllability of each hazardous event, by the rider or other persons involved in the operational
situation is estimated based on a defined rationale for each hazardous event. The controllability is
assigned to one of the controllability classes: C0, C1, C2 or C3.
An MSIL is determined for each hazardous event based on the classification of severity, probability of
exposure and controllability. Four MSILs are defined: MSIL A, MSIL B, MSIL C and MSIL D, where MSIL
A is representing the least stringent and MSIL D the most stringent level. QM is not an MSIL, but can be
specified in the hazard analysis and risk assessment.
Each assessment is based on available or applicable data as well as on expert judgment, the
interpretation of such data can vary among analyses.
5.2 Examples of HARA
5.2.1 General
There are different approaches possible for selecting the appropriate values of E, S and C. Possible
sources for values can be guidelines, technical papers, ISO 26262-12:2018 Annex B, government
statistics, expert judgements or measured data from equivalent motorcycles. The source can
...