CEN/TR 17833:2022

SLOVENSKI STANDARD
01-september-2022
Železniške naprave - Navodilo za uporabo simulacij - Navodilo o uporabi simulacij
za dokazovanje skladnosti s tehničnimi in regulativnimi zahtevami ter o vnašanju
in razvoju simulacijskih zahtev v standarde
Railway applications - Guidance for the use of simulations - Guidance for the use of
simulations to demonstrate compliance with technical and regulatory requirements and
on the introduction and development of simulation requirements into standards
Bahnanwendungen - Leitfaden für den Einsatz von Simulationen - Leitfaden für den
Einsatz von Simulationen zum Nachweis der Einhaltung technischer und regulatorischer
Anforderungen sowie zur Einführung und Entwicklung von Simulationsanforderungen in
Normen
Ta slovenski standard je istoveten z: CEN/TR 17833:2022
ICS:
01.120 Standardizacija. Splošna Standardization. General
pravila rules
45.020 Železniška tehnika na Railway engineering in
splošno general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

CEN/TR 17833
TECHNICAL REPORT
RAPPORT TECHNIQUE
June 2022
TECHNISCHER BERICHT
ICS
English Version
Railway applications - Guidance for the use of simulations
- Guidance for the use of simulations to demonstrate
compliance with technical and regulatory requirements
and on the introduction and development of simulation
requirements into standards
Bahnanwendungen - Leitfaden für den Einsatz von
Simulationen - Leitfaden für den Einsatz von
Simulationen zum Nachweis der Einhaltung
technischer und regulatorischer Anforderungen sowie
zur Einführung und Entwicklung von
Simulationsanforderungen in Normen

This Technical Report was approved by CEN on 24 May 2022. 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
© 2022 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN/TR 17833:2022 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
1 Scope . 4
2 Normative references . 4
3 Terms and definitions . 4
4 Introduction . 6
4.1 Background . 6
4.2 Context . 7
5 Principles governing the use of simulation . 7
5.1 General . 7
5.2 Verification of simulation tools. 8
5.3 User capabilities/qualification . 9
5.4 Verification and validation of simulation models . 9
5.4.1 Verification of models . 9
5.4.2 Validation of models . 9
5.5 Specific additional conditions for Hardware- and Software in the Loop . 10
5.6 Documentation when using simulations . 10
6 Guidance for technical assessors (acceptance of simulation results) . 10
7 Guidance for WG Convenors . 12
Annex A (informative) Examples where simulations have been substituted for physical
tests on the real system . 15
Annex B (informative) Example of replacement of physical testing on the real system by
simulation – aerodynamic pressures at the trackside . 17
B.1 Introduction . 17
B.2 Analysis of uncertainty and impact on output parameter Δp . 17
σ
Bibliography . 20

European foreword
This document (CEN/TR 17833:2022) 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.
1 Scope
The aim of this document is to help CEN/CENELEC Working Group convenors and experts to
promote/develop simulation in their standards as an alternative to physical tests on the real system for
proving conformity. It can also provide useful guidance to assessors in the railway sector in approving
simulations where they are not yet specifically defined or where physical tests on the real system are not
defined in standards. Consequently, this document is also relevant to companies developing and applying
simulations with the intention to achieve their acceptance for the purpose of system validation. It is not
intended to provide technical guidance on applying simulations in general.
Where simulations are already introduced in existing standards, this guide is not intended to modify the
specified requirements. However, technical harmonisation between standards might benefit from this
guide for the introduction of additional alternative methods for simulations.
This document principally covers:
— numerical simulation, using complex methods or using simple spreadsheets methods;
— hardware and software in the loop;
— mathematical models solved using numerical methods or iteration, including spreadsheets.
It does not cover the following, although the general principles outlined can be applied to these methods:
— laboratory tests of components;
— fatigue rig tests;
— model scale tests;
— mathematical models solved analytically.
NOTE Due to the limited experience in the railway sector in the application of data-based (as opposed to model-
based) simulations, for example using artificial intelligence (AI), neural networks, big data, etc., this approach is not
further developed at this stage in this document.
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.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at https://www.electropedia.org/
— ISO Online browsing platform: available at https://www.iso.org/obp
3.1
simulation (action and object)
(action) use of a similar or equivalent system to imitate a real system so that it behaves like or appears
to be the real system; (object) similar or equivalent system used to imitate a real system
Note 1 to entry: Simulation can be mathematical, analogue or scale modelling. Mathematical simulation includes
analytical and numerical calculation.
[SOURCE, ISO 16781:2013, 2.9, modified, Note 1 has been added.]
3.2
numerical simulation
simulation based on numerical methods
3.3
test
technical operation that consists of applying to the object a set of environmental and operating conditions
under a specified procedure.
Note 1 to entry: A test can be carried out to determine one or more characteristics of a given object, process or
service according to a specified procedure. It can be used for different purposes (verifying requirements, calibration,
test cases and correct implementation of a model, etc.).
Note 2 to entry: A test can be conducted on the real system, or by entirely or partially using simulation
(simulation testing)
[SOURCE: IEV modified, ISO/IEC Guide 2 (13.1), notes 1 and 2 have been added]
3.4
simulation tool
in house, vendor or open source framework in which one may develop or embed models enabling the
execution of tests. It can be software and/or hardware and parts of the real system can be installed in the
tool.
3.5
model
mathematical and/or physical representation of a system or a process
3.6
numerical model
numerical representation of a mathematical model
3.7
verification (of simulation)
process of determining that a simulation in its tool environment produces expected results according to
the underlying model
3.8
validation (of simulation)
process of determining the degree to which a model is an accurate representation of the real system in
its environment
[ASME V&V 10 2006, modified] [ASME V&V 40 2018, modified]
3.9
system validation
process of proving conformity to system requirements, ensuring that the system is fit for its intended use
in its intended operational environment
3.10
regression testing
testing required to determine that a change to a system (e.g. a model or a tool) has not adversely affected
functionality, reliability or performance and has not introduced additional defects
[SOURCE, ISO/IEC 27034-7:2018, 3.15, modified.]
3.11
environment
external aspects influencing the behaviour of a system
3.12
user
entity using the simulation
3.13
certification
third-party attestation related to components, sub-systems or systems
3.14
hardware in the loop simulation
type of simulation, in which some parts of the system or its environment are implemented or modelled by
real equipment
Note 1 to entry: Hardware in the loop simulations are characterised by a two-way coupling between the
simulated and the real components.
[SOURCE: IEC 16781:2013, 2.5, modified, note 1 added]
3.15
software in the loop simulation
type of simulation, in which a software that is executable on the real system is interfaced with simulation
models
4 Introduction
4.1 Background
The rationale for producing this document is the perception that physical testing on the real system for
train, infrastructure and command and control system certification leads to:
— excessive costs;
— delays bringing products to market.
The use of simulation is widespread in the automotive and the aerospace sectors, both for design and
validation. The challenge is for the European railway sector to examine its certification processes and
allow for the use of simulation methods as well as physical testing on the real system for system
validation, where it is possible and safe. In the majority of instances, the demonstration methods are
defined in CEN and CENELEC standards.
At the JPC Rail (Sector Forum Rail) meeting in March 2018, the issue of promoting the use of simulation
within the Railway Sector was raised. In response, three steps were proposed by CEN:
a) to set up a survey group to identify and ideally respond to transversal questions and needs to support
WG Convenors and experts to introduce or to further define simulation requirements in their
standards. It was foreseen that the outcome of the Survey Group would be a preliminary issue of a
guide;
b) to urge current CEN and CENELEC Working Groups’ conveners and experts to consider either
introducing or further defining existing simulation requirements within standards under their
responsibilities;
c) to invite the ERA and the EC to promote simulation approaches throughout the regulatory framework
whenever possible.
4.2 Context
Historically, the demonstration of safety and conformity to standards for obtaining the certification of
rolling stock, fixed installations, control-command systems and infrastructure has been mainly based on
physical tests on the real system.
Although already widely used in the design and pre-validation of sub-systems, simulation is still relatively
rarely applied to improve and accelerate the system validation phase, where physical tests on
...