SIST-TP CEN/TR 17696:2021
(Main)Railway applications - Vehicle Maintenance - Guide for identification and management of Safety Critical Components for railway vehicles
Railway applications - Vehicle Maintenance - Guide for identification and management of Safety Critical Components for railway vehicles
The objective of this document is to provide an overview of the SCCs requirements captured from the current legislation and the actors involved in their fulfilment.
In addition, this document aims to promote a common understanding of those requirements together with practical arrangements to fulfil them in a proper way and giving guidance for the SCCs identification and management.
The objective of the document is neither to produce an applicable list of SCCs nor to provide for examples of SCCs.
This document is applicable to vehicles only. The definition of "vehicle" is as in Art. 3(21) of the Safety Directive [3].
Bahnanwendungen - Fahrzeuginstandhaltung - Leitfaden zur Identifizierung und dem Management von Sicherheitskritischen Komponenten für Schienenfahrzeuge
Dieses Dokument zielt darauf ab, einen Überblick zu geben über die aus der aktuellen Gesetzgebung resultierenden Anforderungen und die an ihrer Erfüllung beteiligten Akteure.
Darüber hinaus soll das Dokument ein gemeinsames Verständnis dieser Anforderungen zusammen mit praktischen Vorkehrungen zu ihrer ordnungsgemäßen Erfüllung vermitteln und Leitlinien zur Identifizierung und Management von SCC geben.
Ziel des Dokuments ist weder die Erstellung einer anwendbaren Liste von SCC noch die Bereitstellung von Beispielen für SCC.
Dieses Dokument ist nur auf Fahrzeuge anwendbar. Die Definition von „Fahrzeug“ entspricht der Definition in Artikel 3 Absatz 21 der Sicherheitsrichtlinie [3].
Applications Ferroviaires - Maintenance des véhicules - Guide pour l’identification et le management des Composants Critiques de Sécurité pour les véhicules ferroviaires
Le présent document vise à proposer une vue d'ensemble des exigences relatives aux SCC à partir de la législation en vigueur et des acteurs impliqués dans sa mise en application.
De surcroît, ce document a vocation à promouvoir une compréhension commune de ces exigences, ainsi que des dispositions pratiques adoptées pour les satisfaire correctement et fournir des lignes directrices pour l'identification et la gestion des SCC.
Il ne vise ni à produire une liste des SCC applicables, ni à fournir des exemples de SCC.
Le présent document s'applique aux véhicules exclusivement. La définition du terme « véhicule » est celle de l'Art. 3(21) de la Directive de sécurité [3].
Železniške naprave - Vzdrževanje vozil - Vodilo za prepoznavanje in ravnanje z varnostno kritičnimi sestavnimi deli železniških vozil
General Information
Standards Content (Sample)
SLOVENSKI STANDARD
SIST-TP CEN/TR 17696:2021
01-december-2021
Železniške naprave - Vzdrževanje vozil - Vodilo za prepoznavanje in ravnanje z
varnostno kritičnimi sestavnimi deli železniških vozil
Railway applications - Vehicle Maintenance - Guide for identification and management of
Safety Critical Components for railway vehicles
Bahnanwendungen - Fahrzeuginstandhaltung - Leitfaden zur Identifizierung und dem
Management von Sicherheitskritischen Komponenten für Schienenfahrzeuge
Applications Ferroviaires - Maintenance des véhicules - Guide pour l’identification et le
management des Composants Critiques de Sécurité pour les véhicules ferroviaires
Ta slovenski standard je istoveten z: CEN/TR 17696:2021
ICS:
45.060.01 Železniška vozila na splošno Railway rolling stock in
general
SIST-TP CEN/TR 17696:2021 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
---------------------- Page: 1 ----------------------
SIST-TP CEN/TR 17696:2021
---------------------- Page: 2 ----------------------
SIST-TP CEN/TR 17696:2021
CEN/TR 17696
TECHNICAL REPORT
RAPPORT TECHNIQUE
October 2021
TECHNISCHER BERICHT
ICS 45.060.01
English Version
Railway applications - Vehicle Maintenance - Guide for
identification and management of Safety Critical
Components for railway vehicles
Applications Ferroviaires - Maintenance des véhicules - Bahnanwendungen - Fahrzeuginstandhaltung -
Guide pour l'identification et le management des Leitfaden zur Identifizierung und dem Management
Composants Critiques de Sécurité pour les véhicules von Sicherheitskritischen Komponenten für
ferroviaires Schienenfahrzeuge
This Technical Report was approved by CEN on 20 September 2021. It has been drawn up by the Technical Committee CEN/TC
256.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, 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
© 2021 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN/TR 17696:2021 E
worldwide for CEN national Members.
---------------------- Page: 3 ----------------------
SIST-TP CEN/TR 17696:2021
CEN/TR 17696:2021 (E)
Contents Page
Foreword . 3
Introduction . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Symbols and abbreviations . 6
5 SCCs definition . 6
5.1 General . 6
5.2 Identification of accidents and consequences related to SCCs definition . 7
6 SCCs requirements: actors and vehicles involved . 8
6.1 General . 8
6.2 SCCs requirements and actors involved . 8
6.3 SCCs requirements and their applicability to railway vehicles . 9
6.4 Tables of SCCs requirements with actors and vehicles involved . 10
7 SCCs management process and identification . 13
7.1 SCCs management process . 13
7.2 SCCs deliverables. 18
7.3 Methods for the identification of SCCs . 19
7.3.1 General . 19
7.3.2 Identification of SCCs through a bottom-up method . 20
7.3.3 Identification of SCCs through a top-down method . 24
Annex A (informative) SCCs references capture . 27
Annex B (informative) Comprehension of SCCs definition . 34
Annex C (informative) Considerations on specific wording of the SCCs definition . 39
Annex D (informative) Using statistics of “serious accidents” . 40
Bibliography . 42
2
---------------------- Page: 4 ----------------------
SIST-TP CEN/TR 17696:2021
CEN/TR 17696:2021 (E)
Foreword
This document (CEN/TR 17696:2021) has been prepared by Technical Committee CEN/TC 256 “Railway
applications”, the secretariat of which is held by DIN.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
Any feedback and questions on this document should be directed to the users’ national standards body.
A complete listing of these bodies can be found on the CEN website.
3
---------------------- Page: 5 ----------------------
SIST-TP CEN/TR 17696:2021
CEN/TR 17696:2021 (E)
Introduction
The following document is focused on the new concept of Safety Critical Component (SCC) introduced in
the recent framework of the European legislation.
4
---------------------- Page: 6 ----------------------
SIST-TP CEN/TR 17696:2021
CEN/TR 17696:2021 (E)
1 Scope
The objective of this document is to provide an overview of the SCCs requirements captured from the
current legislation and the actors involved in their fulfilment.
In addition, this document aims to promote a common understanding of those requirements together
with practical arrangements to fulfil them in a proper way and giving guidance for the SCCs identification
and management.
The objective of the document is neither to produce an applicable list of SCCs nor to provide for examples
of SCCs.
This document is applicable to vehicles only. The definition of “vehicle” is as in Art. 3(21) of the Safety
Directive [3].
2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
renewal
any major substitution work on a subsystem or part subsystem which does not change the overall
performance of the subsystem
3.2
upgrade
upgrading
any major modification work on a subsystem or part subsystem which improves the overall performance
of the subsystem
3.3
refurbishment
programme of interior/exterior work, other than routine maintenance or repair, undertaken on a railway
vehicle to restore or enhance the level of design and performance
3.4
engineering change
change to a railway vehicle, including control software, in the area of design, construction or maintenance
which affects, or potentially affects, conformity to applicable requirements
5
---------------------- Page: 7 ----------------------
SIST-TP CEN/TR 17696:2021
CEN/TR 17696:2021 (E)
4 Symbols and abbreviations
For the purposes of this document, the following abbreviations apply with reference to Article 15 of
Regulation (EU) 2018/545 (Practical arrangements for vehicle authorisation).
Table 1 — Abbreviations
Symbol Designation
SCC/SCCs Safety Critical Component/s
REX Return on Experience
TSI Technical Specification for Interoperability
REF Reference
CSI Common Safety Indicator
CSM Common Safety Method
ECM Entity in Charge of Maintenance
RU Railway Undertaking
5 SCCs definition
5.1 General
The definition of SCCs is the combination of REF13 or REF14 (see Annex A for REFs captured) and the
definition of “serious accident” as in Article 3(12) of the Safety Directive [3].
The definition of “safety critical components” in REF13 and REF14 is the same. Here below REF14 is
shown in detail:
REF14
The Annex to Regulation (EU) No 1302/2014 (TSI Loc & Pas) is amended as follows:
……
(39) point (4) of section 4.2.12.1 is replaced by the following:
‘(4) The documentation also includes a list of safety critical components. Safety critical components are
components for which a single failure has a credible potential to lead directly to a serious accident as defined
in Article 3(12) of Directive (EU) 2016/798.
The “serious accident” captured from Article 3(12) of the Safety Directive [3] is defined as:
Article 3 Definitions
(12) ‘serious accident’ means any train collision or derailment of trains resulting in the death of at least
one person or serious injuries to five or more persons or extensive damage to rolling stock, the infrastructure
or the environment, and any other accident with the same consequences which has an obvious impact on
railway safety regulation or the management of safety; ‘extensive damage’ means damage that can be
immediately assessed by the investigating body to cost at least EUR 2 million in total;
6
---------------------- Page: 8 ----------------------
SIST-TP CEN/TR 17696:2021
CEN/TR 17696:2021 (E)
Based on the above-mentioned references, the following is the complete definition of Safety Critical
Components:
Safety critical components are components for which a single failure has a credible potential to lead
directly to:
— any train collision or derailment of trains resulting in the death of at least one person or serious
injuries to five or more persons or extensive damage to rolling stock, the infrastructure or the
environment; and
— any other accident with the same consequences which has an obvious impact on railway safety
regulation or the management of safety;
‘extensive damage’ means damage that can be immediately assessed by the investigating body to cost at
least EUR 2 million in total.
5.2 Identification of accidents and consequences related to SCCs definition
As shown in 5.1, the SCCs definition is fundamentally based on the occurrence of a “serious accident”.
The “serious accident” definition identifies typical railway accidents and their specific consequences,
which aids the comprehension of the SCCs definition.
Based on the definitions reported in Annex B, a list of typical railway accidents and a list of consequences
related to the definition of SCCs can be compiled. These lists can be used for subsequent analyses in order
to identify the safety critical components.
The following is a non-exhaustive list of accidents, related to the definition of SCCs, caused by the single
failure of a vehicle’s component:
Table 2 — SCCs - List of accidents
derailment
collision collision of train with obstacle collision of train with rail
vehicle
level crossing accident
accident to persons involving persons falling from trains passengers in station hurt by
rolling stock in motion train
persons hit by a railway vehicle
or by an object attached to, or
that has become detached from,
the vehicle
fire/explosion fires in an area inside or outside
the railway premises
dangerous goods release during pollution of an area by liquid,
transport solid or gas release of goods
objects detached from trains
electrocution
other accidents causing damage material damage to an area (e.g. damage to rolling stocks
trees pulled down by rolling stock
in motion, infrastructure
damage, railway premises, …)
7
---------------------- Page: 9 ----------------------
SIST-TP CEN/TR 17696:2021
CEN/TR 17696:2021 (E)
A more complete list of accidents to be considered can be obtained through experience, historical data
and statistics.
The consequences to be considered as the effect of the accident are the following (single effect or
combination of effects):
Table 3 — SCCs – List of consequences
death of at least one person
serious injuries to five or more persons
damage to rolling stock, the infrastructure or the environment assessed to cost at least 2 million EUR in
total
6 SCCs requirements: actors and vehicles involved
6.1 General
The recent framework of the European legislation contains many new inputs related specifically to SCCs.
These inputs state the SCCs requirements to be accomplished and the actors involved in their
accomplishment.
Annex A contains the list of SCCs references and requirements captured from the legislation.
6.2 SCCs requirements and actors involved
The following table collects the outcome of the capture process in Annex A splitting the SCCs
requirements among the different actors involved.
Table 4 — SCCs Requirements capture
Doc. Short Title REF N. Actors involved
Ref.
N°
[1] Agency REF1 Agency
regulation
[2] Interoperability REF2 Commission
Directive
REF3 All
[3] Safety Directive REF4 Commission
REF5 ECM, ECM functions
[4] ECM Regulation REF6 Manufacturer, ECM
REF7 ECM, maintenance functions
REF8 All the actors involved
REF9 Manufacturers, ECM, Keeper, ECM functions
REF10 ECM, ECM maintenance development function
REF11 ECM, ECM maintenance delivery function
[5] REF12 Manufacturer, Agency
TSIs Loc&Pas
REF13 Manufacturer, RU/Keeper, ECM
and WAG
REF14 Manufacturer, RU, ECM
revision
8
---------------------- Page: 10 ----------------------
SIST-TP CEN/TR 17696:2021
CEN/TR 17696:2021 (E)
6.3 SCCs requirements and their applicability to railway vehicles
To make clear the applicability of SCCs requirements in the field of railway vehicles, it is necessary to
distinguish between two categories of vehicles:
— new vehicle;
— existing vehicle.
This distinction is made as not all the SCCs requirements are applicable to both the categories of vehicles.
The tables in next section are split among these two categories of vehicles.
For convenience, a new vehicle is a vehicle for which an applicant has requested from the authorising
entity the vehicle type authorisation for placing on the market/authorisation for placing in service under
the new legislation (complying with Regulation 2018/545 and using the One-Stop-Shop of Agency).
An existing vehicle is a vehicle that does not meet the criteria of a new vehicle.
The SCCs requirements for new vehicles also apply to existing vehicles that have a vehicle type
authorisation for placing on the market/authorisation for placing in service following engineering
change/renewal/upgrading/refurbishment, only for the parts of the vehicle related to engineering
change/renewal/upgrading/refurbishment.
In that case, the entity managing the change (holder of the vehicle type authorisation or other) plays
the same role as the Manufacturer (see 6.4 and 7.1 for details).
In addition, the applicant for the vehicle type authorisation is responsible for compiling the technical file
that is to accompany the ‘EC’ declaration of verification when the application is submitted (see Art. 15 of
the Interoperability Directive [2]).
When the vehicle type authorisation is issued, the applicant becomes the holder of the vehicle type
authorisation and keeps a copy of the technical file throughout the service life of the vehicle (see Annex
IV 2.6 of the Interoperability Directive [2]).
In the case of a change to the vehicle, the technical file is kept up to date by the entity managing the change
to the vehicle, that is the holder of the vehicle type authorisation or other entity managing the change
(see Regulation (EU) 2018/545, Articles 15 and 16).
Usually, the detailed content of the different documents of the technical file is prepared by the
Manufacturer of the vehicle, where the Manufacturer itself may play the role of “applicant”.
The maintenance documentation is a part of the technical file and it is given by the applicant (directly
or via the Keeper) to the ECM to make it able to manage and implement the maintenance of the vehicle.
The ECM is responsible for arranging the first “maintenance file” by adapting the maintenance
documentation to the real operating conditions, performances required and return on experience and to
keep updated the maintenance file throughout the lifecycle of the vehicle.
In addition, in the case of existing vehicle, the ECM is responsible for managing the maintenance
documentation (see Art. 14 3(b) of the Safety Directive [3]) and keeping it updated throughout the
lifecycle of the vehicle.
The technical file and the maintenance file play a fundamental role in the accomplishment of the SCCs
requirements.
9
---------------------- Page: 11 ----------------------
SIST-TP CEN/TR 17696:2021
CEN/TR 17696:2021 (E)
6.4 Tables of SCCs requirements with actors and vehicles involved
This clause sets out in three tables the SCCs requirements among actors and vehicles involved in the main
phases of the life. Each table represents the responsibilities of each actor or group of actors in respect of
new or existing vehicles.
The tables do not consider the SCCs requirements related to the Agency or the Commission or any
sentence from the “whereas” section of the references captured as requirements to be accomplished (see
Annex A).
When developing its activities and preparing documentation, the Manufacturer/Entity managing the
change is responsible for:
Table 5 — SCCs requirements for Manufacturer/Entity managing the change
Legislation References Phase Requirement New Existing
vehicles vehicles
Interop. REF3 Design carrying out design, construction X 1
X
Directive or assembly of SCCs, and more
particularly of the components
involved in train movements, in
such a way to guarantee the
corresponding safety level of the
network in normal and degraded
situations
TSIs REF13 and Design inserting a SCCs list into the X 1
X
REF 14 technical file
TSIs REF13 and Design inserting a SCCs list into the X 1
X
REF 14 maintenance description file
together with specific servicing,
maintenance and
servicing/maintenance traceability
requirements
TSIs REF13 and Design inserting a SCCs list into the X 1
X
REF 14 operation documentation together
with specific operational and
operational traceability
requirements
TSIs REF13 and Design specifying precedents, principles X 1
X
REF 14 and methods used to identify SCCs
and their specific operational,
servicing, maintenance and
traceability requirements inside
the Maintenance Design
Justification File
TSIs REF13 and Design developing specific operational X 1
X
REF14 and operational traceability
requirements during the design
phase
TSIs REF13 and Design identifying specific servicing, X 1
X
REF 14 maintenance and maintenance
traceability requirements during
the design phase
10
---------------------- Page: 12 ----------------------
SIST-TP CEN/TR 17696:2021
CEN/TR 17696:2021 (E)
Legislation References Phase Requirement New Existing
vehicles vehicles
TSIs REF13 and Operation collaborating with the RU/Keeper X X
REF 14 to develop specific operational and
operational traceability
requirements after the vehicles
have entered into operation
TSIs REF13 and Operation collaborating with the ECM to X X
REF 14 identify SCCs and their specific
servicing, maintenance and
maintenance traceability
requirements after the vehicles
have entered into operation
ECM REF8 Design/Operation considering the SCCs definition X 1
X
Regulation during design and in the service
life of the vehicle to identify new
SCC or manage its changes
ECM REF9 Design/Operation managing information and X 1
X
Regulation maintenance instructions of SCCs
in the technical file
ECM REF9 Operation confirming if new SCC identified by X X
Regulation the ECM is safety-critical through a
risk assessment taking into
account the use and environment
of the component
ECM REF9 Operation providing technical and X X
Regulation engineering support about SCCs
and their safe integration, when
the ECM or Keeper address a
request
NOTE 1 Only in the case of design for engineering change/renewal/upgrading/refurbishment of existing
vehicles, for the Entity managing the change (Manufacturer or other entity), limited to only the parts of the vehicle
related to engineering change/renewal/upgrading/refurbishment.
11
---------------------- Page: 13 ----------------------
SIST-TP CEN/TR 17696:2021
CEN/TR 17696:2021 (E)
When developing its activities and preparing documentation, the ECM is responsible for:
Table 6 — SCCs requirements for ECM
Legislation References Requirement New Existing
vehicles vehicles
Interop. REF3 carrying out the maintenance and monitoring of SCCs, and X X
Directive more particularly of the components involved in train
movements, in such a way to guarantee the corresponding
safety level of the network in normal and degraded
situations
ECM REF10 [maintenance development function] having a procedure to X X
Regulation identify and manage SCCs
ECM REF10 [maintenance development function] having a procedure X X
Regulation for the competence management process taking into
account maintenance activities on SCCs
ECM REF10 [maintenance development function] having a procedure to X X
Regulation guarantee traceability of the vehicle’s configuration
documentation related to SCCs
ECM REF11 [maintenance delivery function] having a procedure for the X X
Regulation competence management process taking into account
maintenance activities on SCCs
ECM REF9 taking into account the initial Manufacturer SCCs list and X 2
--
Regulation the specific maintenance instructions recorded into the
technical file
Safety REF5 identifying and correctly managing the maintenance X X
Directive activities affecting safety and SCCs and identifying and
properly managing their changes through REX and the
application of the Common Safety Method for risk
assessment
ECM REF7 meeting SCCs management requirements specified inside X X
Regulation ECM Regulation [4]
ECM REF8 consider the SCCs definition in the service life of the X X
Regulation vehicle to identify new SCC or manage its changes
ECM REF9 inform without delay Manufacturer, the holder of the X X
Regulation vehicle type authorisation and the holder of the vehicle
authorisation (if these parties can be identified), when it
becomes aware of evidence that a new SCC is identified
ECM REF9 inform the rail sector and the rail supply industry about X X
Regulation new or unexpected safety relevant findings when the
related risks are relevant for more actors and are likely to
be poorly controlled. To do this, the ECM is required to use
SAIT or other informatics tool provided by the Agency for
that information
ECM REF9 providing, directly or via the Keeper, information about X X
Regulation SCCs to railway undertakings and infrastructure managers
operating the vehicles, keepers, manufacturers, holders of
vehicles authorisations and holders of the type
authorisation of vehicles, subsystems or components, as
most appropriate, and inform them of exceptional
maintenance findings beyond wear and tear
12
---------------------- Page: 14 ----------------------
SIST-TP CEN/TR 17696:2021
CEN/TR 17696:2021 (E)
Legislation References Requirement New Existing
vehicles vehicles
ECM REF9 as appropriate, adjusting procedures to ensure monitoring X X
Regulation and safe maintenance of the component when a new SCC
is identified
ECM REF9 managing safety critical components and appropriate X X
Regulation maintenance instructions as well as relevant maintenance
activities in the maintenance file or documentation
referred to in Article 14 of the Safety Directive [3]
ECM REF9 where necessary, addressing a request to the X X
Regulation Manufacturer, directly or via the Keeper, for technical and
engineering support about SCCs and their safe integration
TSIs REF13 and collaborating with the Manufacturer to develop specific X X
REF14 servicing, maintenance and maintenance traceability
requirements after the vehicles have entered into
operation
NOTE 2 It is assumed that no SCCs list will have been provided by the Manufacturer for existing vehicles.
When developing its activities and preparing documentation the RU/Keeper is responsible for:
Table 7 — SCCs requirements for RU/Keeper
Legislation Reference Requirement New Existing
vehicles vehicles
Interop. REF3 carrying out monitoring of SCCs, and more particularly of X X
Directive the components involved in train movements, in such a
way to guarantee the corresponding safety level of the
network in normal and degraded situations
ECM REF9 where necessary, addressing a request to the X X
Regulation Manufacturer for technical and engineering support about
SCCs and their safe integration
TSIs REF13 and collaborating with the Manufacturer to develop specific X X
REF14 operational and operational traceability requirements
after vehicles have entered into operation
7 SCCs management process and identification
7.1 SCCs management process
The identification and management of SCCs starts as part of the design phase under the responsibility of
the vehicle Designer/Manufacturer from the concept phase and, when the vehicle is in
operation/maintenance phases, through the collaboration and exchange of information with
ECM/RU/Keeper (references on the life-cycle phases applicable to a vehicle can be found in EN 50126-
1:2017).
Generally, to guarantee the safety level in normal and degraded situations, as requested by the relevant
TSIs, Designers/Manufacturers are requested to carry out design, construction or assembly for satisfying
at least safety requirements.
As regards SCCs, it is expected that Designers/Manufacturers will seek to minimise or eliminate SCCs by
means of architectural and functional design choices (see also 5.9 of EN 50126-1:2017). However, where
13
---------------------- Page: 15 ----------------------
SIST-TP CEN/TR 17696:2021
CEN/TR 17696:2021 (E)
it is not practicable to ‘design out’ a SCC, it is crucial that the component is clearly identified, managed
and notified. To do so for new vehicles, the Manufacturer is required to:
— identify SCCs during the concept/design phase by means of risk-based analysis;
— insert a SCCs list in the technical file/maintenance description file/operation documentation
together with their specific requirements for:
— operation, servicing, maintenance;
— operational, servicing and maintenance traceability;
— specify precedents, principles and methods used to identify SCCs and their specific requirements
inside the Maintenance Design Justification File.
These SCCs deliverables, being part of the technical documentation of the vehicle, need to be notified
to ECMs/RUs/Keepers to support them during operation/maintenance phases and to update, where
necessary, the technical file of the vehicle.
The same process is also valid in the case of engineering change/renewal/upgrading/refurbishment of
the vehicle, where in this case the designer/Manufacturer/Entity managing the engineering
change/renewal/upgrading/refurbishment is called to provide for the SCCs deliverables.
As a consequence of the requirements tables as in 6.4, neither Manufacturers/Entities managing the
change nor ECMs are obliged to identify retrospectively SCCs for existing vehicles except in the case of
engineering change/renewal/upgrading/refurbishment, only for the parts of the vehicle related to
engineering change/renewal/upgrading/refurbishment.
However, for existing and new vehicles, if during its routine maintenance activities (see Table 8 for
details) an ECM becomes aware of evidence suggesting a component not previously identified as safety
critical should be considered as such, it must notify:
— the Manufacturer;
— the holder of the vehicle type authorisation; and
— the holder of the vehicle authorisation.
After receiving this notification, the Manufacturer, when it
...
SLOVENSKI STANDARD
kSIST-TP FprCEN/TR 17696:2021
01-julij-2021
Železniške naprave - Vzdrževanje vozil - Vodilo za prepoznavanje in ravnanje z
varnostno kritičnimi sestavnimi deli železniških vozil
Railway applications - Vehicle Maintenance - Guide for identification and management of
Safety Critical Components for railway vehicles
Bahnanwendungen - Fahrzeuginstandhaltung - Leitfaden zur Identifizierung und dem
Management von Sicherheitskritischen Komponenten für Schienenfahrzeuge
Applications Ferroviaires - Maintenance des véhicules - Guide pour l’identification et le
management des Composants Critiques de Sécurité pour les véhicules ferroviaires
Ta slovenski standard je istoveten z: FprCEN/TR 17696
ICS:
45.060.01 Železniška vozila na splošno Railway rolling stock in
general
kSIST-TP FprCEN/TR 17696:2021 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
---------------------- Page: 1 ----------------------
kSIST-TP FprCEN/TR 17696:2021
---------------------- Page: 2 ----------------------
kSIST-TP FprCEN/TR 17696:2021
FINAL DRAFT
TECHNICAL REPORT
FprCEN/TR 17696
RAPPORT TECHNIQUE
TECHNISCHER BERICHT
May 2021
ICS 45.060.01
English Version
Railway applications - Vehicle Maintenance - Guide for
identification and management of Safety Critical
Components for railway vehicles
Applications Ferroviaires - Maintenance des véhicules - Bahnanwendungen - Fahrzeuginstandhaltung -
Guide pour l'identification et le management des Leitfaden zur Identifizierung und dem Management
Composants Critiques de Sécurité pour les véhicules von Sicherheitskritischen Komponenten für
ferroviaires Schienenfahrzeuge
This draft Technical Report is submitted to CEN members for Vote. It has been drawn up by the Technical Committee CEN/TC
256.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are
aware and to provide supporting documentation.
Warning : This document is not a Technical Report. It is distributed for review and comments. It is subject to change without
notice and shall not be referred to as a Technical Report.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2021 CEN All rights of exploitation in any form and by any means reserved Ref. No. FprCEN/TR 17696:2021 E
worldwide for CEN national Members.
---------------------- Page: 3 ----------------------
kSIST-TP FprCEN/TR 17696:2021
FprCEN/TR 17696:2021 (E)
Contents Page
Foreword . 3
Introduction . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Symbols and abbreviations . 6
5 SCCs definition . 6
5.1 General . 6
5.2 Identification of accidents and consequences related to SCCs definition . 7
6 SCCs requirements: actors and vehicles involved . 8
6.1 General . 8
6.2 SCCs requirements and actors involved . 8
6.3 SCCs requirements and their applicability to railway vehicles . 9
6.4 Tables of SCCs requirements with actors and vehicles involved . 10
7 SCCs management process and identification . 13
7.1 SCCs management process . 13
7.2 SCCs deliverables. 18
7.3 Methods for the identification of SCCs . 19
7.3.1 General . 19
7.3.2 Identification of SCCs through a bottom-up method . 20
7.3.3 Identification of SCCs through a top-down method . 24
Annex A (informative) SCCs references capture . 27
Annex B (informative) Comprehension of SCCs definition . 34
Annex C (informative) Considerations on specific wording of the SCCs definition . 39
Annex D (informative) Using statistics of “serious accidents” . 40
Bibliography . 42
2
---------------------- Page: 4 ----------------------
kSIST-TP FprCEN/TR 17696:2021
FprCEN/TR 17696:2021 (E)
Foreword
This document (FprCEN/TR 17696:2021) has been prepared by Technical Committee CEN/TC 256
“Railway applications”, the secretariat of which is held by DIN.
This document is currently submitted to the Vote on TR.
3
---------------------- Page: 5 ----------------------
kSIST-TP FprCEN/TR 17696:2021
FprCEN/TR 17696:2021 (E)
Introduction
The following document is focused on the new concept of Safety Critical Component (SCC) introduced in
the recent framework of the European legislation.
4
---------------------- Page: 6 ----------------------
kSIST-TP FprCEN/TR 17696:2021
FprCEN/TR 17696:2021 (E)
1 Scope
The objective of this document is to provide an overview of the SCCs requirements captured from the
current legislation and the actors involved in their fulfilment.
In addition, this document aims to promote a common understanding of those requirements together
with practical arrangements to fulfil them in a proper way and giving guidance for the SCCs identification
and management.
The objective of the document is neither to produce an applicable list of SCCs nor to provide for examples
of SCCs.
This document is applicable to vehicles only. The definition of “vehicle” is as in Art. 3(21) of the Safety
Directive [3].
2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
renewal
any major substitution work on a subsystem or part subsystem which does not change the overall
performance of the subsystem
3.2
upgrade
upgrading
any major modification work on a subsystem or part subsystem which improves the overall performance
of the subsystem
3.3
refurbishment
programme of interior/exterior work, other than routine maintenance or repair, undertaken on a railway
vehicle to restore or enhance the level of design and performance
3.4
engineering change
change to a railway vehicle, including control software, in the area of design, construction or maintenance
which affects, or potentially affects, conformity to applicable requirements
5
---------------------- Page: 7 ----------------------
kSIST-TP FprCEN/TR 17696:2021
FprCEN/TR 17696:2021 (E)
4 Symbols and abbreviations
For the purposes of this document, the following abbreviations apply with reference to Article 15 of
Regulation (EU) 2018/545 (Practical arrangements for vehicle authorisation).
Table 1 — Abbreviations
Symbol Designation
SCC/SCCs Safety Critical Component/s
REX Return on Experience
TSI Technical Specification for Interoperability
REF Reference
CSI Common Safety Indicator
CSM Common Safety Method
ECM Entity in Charge of Maintenance
RU Railway Undertaking
5 SCCs definition
5.1 General
The definition of SCCs is the combination of REF13 or REF14 (see Annex A for REFs captured) and the
definition of “serious accident” as in Article 3(12) of the Safety Directive [3].
The definition of “safety critical components” in REF13 and REF14 is the same. Here below REF14 is
shown in detail:
REF14
The Annex to Regulation (EU) No 1302/2014 (TSI Loc & Pas) is amended as follows:
……
(39) point (4) of section 4.2.12.1 is replaced by the following:
‘(4) The documentation also includes a list of safety critical components. Safety critical components are
components for which a single failure has a credible potential to lead directly to a serious accident as defined
in Article 3(12) of Directive (EU) 2016/798.
The “serious accident” captured from Article 3(12) of the Safety Directive [3] is defined as:
Article 3 Definitions
(12) ‘serious accident’ means any train collision or derailment of trains resulting in the death of at least
one person or serious injuries to five or more persons or extensive damage to rolling stock, the infrastructure
or the environment, and any other accident with the same consequences which has an obvious impact on
railway safety regulation or the management of safety; ‘extensive damage’ means damage that can be
immediately assessed by the investigating body to cost at least EUR 2 million in total;
6
---------------------- Page: 8 ----------------------
kSIST-TP FprCEN/TR 17696:2021
FprCEN/TR 17696:2021 (E)
Based on the above-mentioned references, the following is the complete definition of Safety Critical
Components:
Safety critical components are components for which a single failure has a credible potential to lead
directly to:
— any train collision or derailment of trains resulting in the death of at least one person or serious
injuries to five or more persons or extensive damage to rolling stock, the infrastructure or the
environment; and
— any other accident with the same consequences which has an obvious impact on railway safety
regulation or the management of safety;
‘extensive damage’ means damage that can be immediately assessed by the investigating body to cost at
least EUR 2 million in total.
5.2 Identification of accidents and consequences related to SCCs definition
As shown in 5.1, the SCCs definition is fundamentally based on the occurrence of a “serious accident”.
The “serious accident” definition identifies typical railway accidents and their specific consequences,
which aids the comprehension of the SCCs definition.
Based on the definitions reported in Annex B, a list of typical railway accidents and a list of consequences
related to the definition of SCCs can be compiled. These lists can be used for subsequent analyses in order
to identify the safety critical components.
The following is a non-exhaustive list of accidents, related to the definition of SCCs, caused by the single
failure of a vehicle’s component:
Table 2 — SCCs - List of accidents
derailment
collision collision of train with obstacle collision of train with rail
vehicle
level crossing accident
accident to persons involving persons falling from trains passengers in station hurt by
rolling stock in motion train
persons hit by a railway vehicle
or by an object attached to, or
that has become detached from,
the vehicle
fire/explosion fires in an area inside or outside
the railway premises
dangerous goods release during pollution of an area by liquid,
transport solid or gas release of goods
objects detached from trains
electrocution
other accidents causing damage material damage to an area (e.g. damage to rolling stocks
trees pulled down by rolling stock
in motion, infrastructure
damage, railway premises, …)
7
---------------------- Page: 9 ----------------------
kSIST-TP FprCEN/TR 17696:2021
FprCEN/TR 17696:2021 (E)
A more complete list of accidents to be considered can be obtained through experience, historical data
and statistics.
The consequences to be considered as the effect of the accident are the following (single effect or
combination of effects):
Table 3 — SCCs – List of consequences
death of at least one person
serious injuries to five or more persons
damage to rolling stock, the infrastructure or the environment assessed to cost at least 2 million EUR in
total
6 SCCs requirements: actors and vehicles involved
6.1 General
The recent framework of the European legislation contains many new inputs related specifically to SCCs.
These inputs state the SCCs requirements to be accomplished and the actors involved in their
accomplishment.
Annex A contains the list of SCCs references and requirements captured from the legislation.
6.2 SCCs requirements and actors involved
The following table collects the outcome of the capture process in Annex A splitting the SCCs
requirements among the different actors involved.
Table 4 — SCCs Requirements capture
Doc. Short Title REF N. Actors involved
Ref. N°
[1] Agency regulation REF1 Agency
[2] Interoperability REF2 Commission
Directive
REF3 All
[3] Safety Directive REF4 Commission
REF5 ECM, ECM functions
[4] ECM Regulation REF6 Manufacturer, ECM
REF7 ECM, ECM functions
REF8 All the actors involved
REF9 Manufacturers, ECM, Keeper, ECM functions
REF10 ECM, ECM maintenance development function
REF11 ECM, ECM maintenance delivery function
[5] REF12 Manufacturer, Agency
TSIs Loc&Pas and WAG
REF13 Manufacturer, RU/Keeper, ECM
revision
REF14 Manufacturer, RU, ECM
8
---------------------- Page: 10 ----------------------
kSIST-TP FprCEN/TR 17696:2021
FprCEN/TR 17696:2021 (E)
6.3 SCCs requirements and their applicability to railway vehicles
To make clear the applicability of SCCs requirements in the field of railway vehicles, it is necessary to
distinguish between two categories of vehicles:
— new vehicle;
— existing vehicle.
This distinction is made as not all the SCCs requirements are applicable to both the categories of vehicles.
The tables in next section are split among these two categories of vehicles.
For convenience, a new vehicle is a vehicle for which an applicant has requested from the authorising
entity the vehicle type authorisation for placing on the market/authorisation for placing in service under
the new legislation (complying with Regulation 2018/545 and using the One-Stop-Shop of Agency).
An existing vehicle is a vehicle that does not meet the criteria of a new vehicle.
The SCCs requirements for new vehicles also apply to existing vehicles that have a vehicle type
authorisation for placing on the market/authorisation for placing in service following engineering
change/renewal/upgrading/refurbishment, only for the parts of the vehicle related to engineering
change/renewal/upgrading/refurbishment.
In that case, the entity managing the change (holder of the vehicle type authorisation or other) plays
the same role as the Manufacturer (see 6.4 and 7.1 for details).
In addition, the applicant for the vehicle type authorisation is responsible for compiling the technical file
that is to accompany the ‘EC’ declaration of verification when the application is submitted (see Art. 15 of
the Interoperability Directive [2]).
When the vehicle type authorisation is issued, the applicant becomes the holder of the vehicle type
authorisation and keeps a copy of the technical file throughout the service life of the vehicle (see Annex
IV 2.6 of the Interoperability Directive [2]).
In the case of a change to the vehicle, the technical file is kept up to date by the entity managing the change
to the vehicle, that is the holder of the vehicle type authorisation or other entity managing the change
(see Regulation (EU) 2018/545, Articles 15 and 16).
Usually, the detailed content of the different documents of the technical file is prepared by the
Manufacturer of the vehicle, where the Manufacturer itself may play the role of “applicant”.
The maintenance documentation is a part of the technical file and it is given by the applicant (directly
or via the Keeper) to the ECM to make it able to manage and implement the maintenance of the vehicle.
The ECM is responsible for arranging the first “maintenance file” by adapting the maintenance
documentation to the real operating conditions, performances required and return on experience and to
keep updated the maintenance file throughout the lifecycle of the vehicle.
In addition, in the case of existing vehicle, the ECM is responsible for managing the maintenance
documentation (see Art. 14 3(b) of the Safety Directive [3]) and keeping it updated throughout the
lifecycle of the vehicle.
The technical file and the maintenance file play a fundamental role in the accomplishment of the SCCs
requirements.
9
---------------------- Page: 11 ----------------------
kSIST-TP FprCEN/TR 17696:2021
FprCEN/TR 17696:2021 (E)
6.4 Tables of SCCs requirements with actors and vehicles involved
This clause sets out in three tables the SCCs requirements among actors and vehicles involved in the main
phases of the life. Each table represents the responsibilities of each actor or group of actors in respect of
new or existing vehicles.
The tables do not consider the SCCs requirements related to the Agency or the Commission or any
sentence from the “whereas” section of the references captured as requirements to be accomplished (see
Annex A).
When developing its activities and preparing documentation, the Manufacturer/Entity managing the
change is responsible for:
Table 5 — SCCs requirements for Manufacturer/Entity managing the change
Legislation References Phase Requirement New Existing
vehicles vehicles
1
Interop. REF3 Design carrying out design, construction X
X
Directive or assembly of SCCs, and more
particularly of the components
involved in train movements, in
such a way to guarantee the
corresponding safety level of the
network in normal and degraded
situations
1
TSIs REF13 and Design inserting a SCCs list into the X
X
REF 14 technical file
1
TSIs REF13 and Design inserting a SCCs list into the X
X
REF 14 maintenance description file
together with specific servicing,
maintenance and
servicing/maintenance traceability
requirements
1
TSIs REF13 and Design inserting a SCCs list into the X
X
REF 14 operation documentation together
with specific operational and
operational traceability
requirements
1
TSIs REF13 and Design specifying precedents, principles X
X
REF 14 and methods used to identify SCCs
and their specific operational,
servicing, maintenance and
traceability requirements inside
the Maintenance Design
Justification File
1
TSIs REF13 and Design developing specific operational X
X
REF14 and operational traceability
requirements during the design
phase
1
TSIs REF13 and Design identifying specific servicing, X
X
REF 14 maintenance and maintenance
traceability requirements during
the design phase
10
---------------------- Page: 12 ----------------------
kSIST-TP FprCEN/TR 17696:2021
FprCEN/TR 17696:2021 (E)
Legislation References Phase Requirement New Existing
vehicles vehicles
TSIs REF13 and Operation collaborating with the RU/Keeper X X
REF 14 to develop specific operational and
operational traceability
requirements after the vehicles
have entered into operation
TSIs REF13 and Operation collaborating with the ECM to X X
REF 14 identify SCCs and their specific
servicing, maintenance and
maintenance traceability
requirements after the vehicles
have entered into operation
1
ECM REF8 Design/Operation considering the SCCs definition X
X
Regulation during design and in the service
life of the vehicle to identify new
SCC or manage its changes
1
ECM REF9 Design/Operation managing information and X
X
Regulation maintenance instructions of SCCs
in the technical file
ECM REF9 Operation confirming if new SCC identified by X X
Regulation the ECM is safety-critical through a
risk assessment taking into
account the use and environment
of the component
ECM REF9 Operation providing technical and X X
Regulation engineering support about SCCs
and their safe integration, when
the ECM or Keeper address a
request
NOTE 1 Only in the case of design for engineering change/renewal/upgrading/refurbishment of existing
vehicles, for the Entity managing the change (Manufacturer or other entity), limited to only the parts of the vehicle
related to engineering change/renewal/upgrading/refurbishment.
11
---------------------- Page: 13 ----------------------
kSIST-TP FprCEN/TR 17696:2021
FprCEN/TR 17696:2021 (E)
When developing its activities and preparing documentation, the ECM is responsible for:
Table 6 — SCCs requirements for ECM
Legislation References Requirement New Existing
vehicles vehicles
Interop. REF3 carrying out the maintenance and monitoring of SCCs, and X X
Directive more particularly of the components involved in train
movements, in such a way to guarantee the corresponding
safety level of the network in normal and degraded
situations
ECM REF10 [maintenance development function] having a procedure to X X
Regulation identify and manage SCCs
ECM REF10 [maintenance development function] having a procedure X X
Regulation for the competence management process taking into
account maintenance activities on SCCs
ECM REF10 [maintenance development function] having a procedure to X X
Regulation guarantee traceability of the vehicle’s configuration
documentation related to SCCs
ECM REF11 [maintenance delivery function] having a procedure for the X X
Regulation competence management process taking into account
maintenance activities on SCCs
2
ECM REF9 taking into account the initial Manufacturer SCCs list and X
--
Regulation the specific maintenance instructions recorded into the
technical file
Safety REF5 identifying and correctly managing the maintenance X X
Directive activities affecting safety and SCCs and identifying and
properly managing their changes through REX and the
application of the Common Safety Method for risk
assessment
ECM REF7 meeting SCCs management requirements specified inside X X
Regulation ECM Regulation [4]
ECM REF8 consider the SCCs definition in the service life of the X X
Regulation vehicle to identify new SCC or manage its changes
ECM REF9 inform without delay Manufacturer, the holder of the X X
Regulation vehicle type and the holder of the vehicle authorisation (if
these parties can be identified), when it becomes aware of
evidence about a new SCC is identified
ECM REF9 inform the rail sector and the rail support industry about X X
Regulation new or unexpected safety relevant findings when the
related risks are relevant for more actors and are likely to
be poorly controlled. To do this, the ECM is required to use
SAIT or other informatics tool provided by the Agency for
that information
ECM REF9 providing, directly or via the Keeper, information about X X
Regulation SCCs to railway undertakings and infrastructure managers
operating the vehicles, keepers, manufacturers, holders of
vehicles authorisations and holders of the type
authorisation of vehicles, subsystems or components, as
most appropriate, and inform them of exceptional
maintenance findings beyond wear and tear
12
---------------------- Page: 14 ----------------------
kSIST-TP FprCEN/TR 17696:2021
FprCEN/TR 17696:2021 (E)
Legislation References Requirement New Existing
vehicles vehicles
ECM REF9 as appropriate, adjusting procedures to ensure monitoring X X
Regulation and safe maintenance of the component when a new SCC
is identified
ECM REF9 managing safety critical components and appropriate X X
Regulation maintenance instructions as well as relevant maintenance
activities in the maintenance file or documentation
referred to in Article 14 of the Safety Directive [3]
ECM REF9 where necessary, addressing a request to the X X
Regulation Manufacturer, directly or via the Keeper, for technical and
engineering support about SCCs and their safe integration
TSIs REF13 and collaborating with the Manufacturer to develop specific X X
REF14 servicing, maintenance and maintenance traceability
requirements after the vehicles have entered into
operation
NOTE 2 It is assumed that no SCCs list will have been provided by the Manufacturer for existing vehicles.
When developing its activities and preparing documentation the RU/Keeper is responsible for:
Table 7 — SCCs requirements for RU/Keeper
Legislation Reference Requirement New Existing
vehicles vehicles
Interop. REF3 carrying out monitoring of SCCs, and more particularly of X X
Directive the components involved in train movements, in such a
way to guarantee the corresponding safety level of the
network in normal and degraded situations
ECM REF9 where necessary, addressing a request to the X X
Regulation Manufacturer for technical and engineering support about
SCCs and their safe integration
TSIs REF13 and collaborating with the Manufacturer to develop specific X X
REF14 operational and operational traceability requirements
after vehicles have entered into operation
7 SCCs management process and identification
7.1 SCCs management process
The identification and management of SCCs starts as part of the design phase under the responsibility of
the vehicle Designer/Manufacturer from the concept phase and, when the vehicle is in
operation/maintenance phases, through the collaboration and exchange of information with
ECM/RU/Keeper (references on the life-cycle phases applicable to a vehicle can be found in EN 50126-
1:2017).
Generally, to guarantee the safety level in normal and degraded situations, as requested by the relevant
TSIs, Designers/Manufacturers are requested to carry out design, construction or assembly for satisfying
at least safety requirements.
As regards SCCs, it is expected that Designers/Manufacturers will seek to minimise or eliminate SCCs by
means of architectural and functional design choices (see also 5.9 of EN 50126-1:2017). However, where
13
---------------------- Page: 15 ----------------------
kSIST-TP FprCEN/TR 17696:2021
FprCEN/TR 17696:2021 (E)
it is not practicable to ‘design out’ a SCC, it is crucial that the component is clearly identified, managed
and notified. To do so for new vehicles, the Manufacturer is required to:
— identify SCCs during the concept/design phase by means of risk-based analysis;
— insert a SCCs list in the technical file/maintenance description file/operation documentation
together with their specific requirements for:
— operation, servicing, maintenance;
— operational, servicing and maintenance traceability;
— specify precedents, principles and methods used to identify SCCs and their specific requirements
inside the Maintenance Design Justification File.
These SCCs deliverables, being part of the technical documentation of the vehicle, need to be notified
to ECMs/RUs/Keepers to support them during operation/maintenance phases and to update, where
necessary, the technical file of the vehicle.
The same process is also valid in the case of engineering change/renewal/upgrading/refurbishment of
the vehicle, where in this case the designer/Manufacturer/Entity managing the engineering
change/renewal/upgrading/refurbishment is called to provide for the SCCs deliverables.
As a consequence of the requirements tables as in 6.4, neither Manufacturers/Entities managing the
change nor ECMs are obliged to identify retrospectively SCCs for existing vehicles except in the case of
engineering change/renewal/upgrading/refurbishment, only for the parts of the vehicle related to
engineering change/renewal/upgrading/refurbishment.
However, for existing and new vehicles, if during its routine maintenance activities (see Table 8 for
details) an ECM becomes aware of evidence suggesting a component not previously identified as safety
critical should be considered as such, it must notify:
— the Manufactur
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.