Research
Brief
Hazard analysis and risk assessment for rail projects
T955 - May 2014
Background
This project was undertaken to take advantage of the opportunities
to improve the efficiency of the management of change processes,
created by European legislative changes and technical
standardisation.
Phase 1 surveyed the industry to understand the current state of
practice in risk management of change, mapping a series of
recommendations to develop tools, techniques, and guidance to
support the rail industry in effective risk management.
In response to those recommendations, Phase 2 has developed tools
and guidance, and tested them in real world applications. Activities
undertaken include: applying the risk management process defined
in annex I of the regulation for the Common Safety Method on Risk
Evaluation and Assessment (CSM REA) to case studies; developing
practitioner level guidance on this risk management process; and
working directly with the Thameslink programme to understand how
the Safety Risk Model (SRM) can be used to support major
infrastructure changes.
Aims
The key objectives of this work were to investigate the extent to
which standardisation of the definitions and tools applied to hazard
identification, analysis, and management would benefit the rail
industry; and to develop definitions and tools where a benefit was
identified. The aim was to reduce the effort required to undertake
repetitive and routine safety analysis tasks, and to allow effort to be
targeted at key areas of novelty or risk at an earlier point in the project
lifecycle.
Specific objectives included:
 Develop a suitable set of practitioner level guidance
documents to support application of the risk management
process required by the CSM REA within the GB rail industry.
 Develop a generic hazard list to support the analysis of railway
system hazards that affect rolling stock. This includes links to
codes of practice that control all or part of the risk associated
with each hazard.
RSSB R&D Programme
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enquirydesk@rssb.co.uk
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Hazard analysis and risk assessment for rail projects
T955 - May 2014
 Use real case studies to test the application of the risk
management process required by the CSM REA and use this
learning to revise and update the other outputs.
 Investigate the use of the RSSB SRM and the safety module of
the Network Modelling Framework (NMF) to support the risk
analysis of major infrastructure changes.
Findings
Guidance on CSM REA
Six guidance documents on application of the CSM REA have been
produced by the project. These are closely aligned to the regulation
and specified at practitioner level, including examples and templates.
Findings from the development of the guidance related to:
 The importance and necessary content of the system definition.
 How hazards need to be managed through application of one
of the risk acceptance principles.
 How the CSM REA closure arguments need to be recorded
within the hazard record.
Development of a generic hazard list for rolling stock
The CSM REA regulation defines a hazard as 'a condition that could
lead to an accident'. The project developed a list of railway system
hazards related to rolling stock defined at the boundary of the railway
system. In other words hazards associated with the operational
railway, rather than faults of a particular technical system. This was
published as an appendix to the Guidance on hazard identification and
classification.
Potential uses of a generic hazard list were developed and tested
including:
 In the hazard identification process, either as a check for
completeness or a starting point.
 To improve communication and the management and transfer
of hazards between the different actors involved in a project.
 To improve efficiency by enabling the re-use of safety work by
future projects.
The hazards in the generic rolling stock hazard list have been defined
independently of causes, which might be varied and technical or
operational.
Difficulties identified with producing and using a generic hazard list,
and mapping risk controls to the causes of the hazards, include:
 It is difficult to define all hazards at the same level, in the current
list some are causes of, or precursors to, others.
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 Some risk controls apply to post-hazard mitigations, either to
prevent an accident from occurring, to prevent it from
escalating, or to reduce the consequences.
 When risk is strongly influenced by 'non-intentional' public
behaviour, it can be difficult to define a hazard at a suitable
level: people can find many ways to harm themselves.
For certain scenarios, the causes of the generic hazards were mapped
to risk controls, such as Codes of Practice. Findings from this mapping
include the necessity to develop a structured database to store such
information. A challenge with this approach is determining how to
reference the relevant requirement in a Code of Practice and keep this
information up to date.
Case studies on the application of the CSM REA
The project undertook two case studies to investigate the application
of the CSM REA.
The first of these involved working with several railway undertakings
(RU) to assess a hypothetical change from driver-guard operations to
driver only operations for passenger trains (DOO(p)).
The work was carried out with support from the Rail Delivery Group
and has generated a template risk assessment for any RUs that plan to
implement DOO(p).
The second case study assessed train dispatch under ERTMS and was
carried out in support of the ERTMS National Programme.
Lessons from the case studies were incorporated in the guidance
material, and included:
 It is important to produce a definition of the system that the
project is delivering at an appropriate level of detail and stage
in the project. This needs to include local factors that can
influence risk, which might be achieved by including more
detailed definitions for a manageable number of representative
locations.
 The Reference Systems Risk Acceptance Principle provides a
powerful method of identifying safety requirements and
determining the acceptability of risk. It is therefore valuable to
involve other organisations that already have experience of the
proposed change in the risk assessment process. However, it
may be difficult in practice to determine whether the reference
system used meets the criteria in the regulation that it should
'still qualify for approval in the Member State where the change
is to be introduced' as this criteria is hypothetical and subject to
interpretation.
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Hazard analysis and risk assessment for rail projects
T955 - May 2014
 The Codes of Practice Risk Acceptance Principle can also be
useful, but is not always straightforward to apply. This is
because requirements in codes of practice often do not identify
the hazards that they are designed to control, and it can be
difficult to demonstrate that codes of practice are sufficient for
controlling the risk to an acceptable level.
Use of the SRM and NMF to provide early-project risk
quantification
The work carried out with the Thameslink programme demonstrated
the value of the SRM as a means of:
 Providing a first approximation to the project risk profile.
 Understanding potential changes to the risk profile due to the
changes.
In terms of quantifying low-frequency, high-consequence hazards,
the predicted risk using the SRM-based tools was significantly lower
than that derived from traditional early-stage risk classification tools,
such as workshop-derived risk matrices.
The work also allowed the partition of risk amongst engineering
disciplines on the Thameslink programme and could drive risk-based
decision making in terms of safety mitigations. This was done with
more rigour than traditional means of directing safety improvements,
and provided added justification.
Quantified risk estimates produced for Thameslink, using the NMF
tool for the risk profile, at the completion of the upgrade programme
identified which hazardous events would be likely to show the
greatest increase (both absolute and normalised) in risk. These were
events whose frequency was driven by passenger journeys, such as
passenger/train interface hazards and slips, trips and falls at stations.
Deliverables
The project has produced a number of deliverables, these include 6
guidance notes on the application of the CSM REA. They are:

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Guidance on planning an application of the CSM REA
Guidance on system definition
Guidance on hazard identification and classification
Guidance on risk evaluation and acceptance
Guidance on safety requirements and hazard management
Guidance on independent assessment
This guidance has been published on the Management of Change
page of the RSSB website. It is currently going through a
multifunctional Standards Committee and will be published on the
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RGSonline website http://www.rgsonline.co.uk as a series of Rail
Industry Guidance Notes in June 2014.
The detailed case study report on the application of CSM REA to the
change from driver-guard to DOO(p) dispatch operations has been
published on SPARK http://www.sparkrail.org and linked from the
Management of Change page of the RSSB website. http://
www.rssb.co.uk/improving-industry-performance/
management-of-change
A final report has been published to include discussion and learning
from the case studies and development of the guidance. It also
discusses the application of the SRM and NMF to major infrastructure
changes with particular reference to the Thameslink programme.
Method
Phase 2 led to the development of guidance that was informed by the
case studies and survey carried out in Phase 1, which had input from
industry practitioners, including the project steering group. It was
structured around a systematic breakdown of the CSM REA
regulation, and aligned to risk management processes that
practitioners would undertake.
The generic hazard list was developed using the data collected in
Phase 1, especially hazard breakdowns used by rolling stock
manufacturers and operators. Detailed research was undertaken
reviewing Technical Standards for Interoperability (TSI), National
Safety Rules (NSR), and National Technical Rules (NTR) for specific
scenarios, to link codes of practice to the causes of hazards.
Phase 2 of the project also undertook 2 case studies, which were
effectively real applications of the CSM REA. For these case studies
work was undertaken alongside actual railway undertakings and
national programmes. This involved developing plans, holding
workshops, and identifying safety measures. The work undertaken in
these case studies provided learning for the guidance and generic
hazard list.
The work to investigate the use of the SRM and NMF models to
support major infrastructure changes was undertaken alongside the
Thameslink programme. This element of the project used data
gathered from Thameslink to model the current and future risk profile
for different parts of the Thameslink route.
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Hazard analysis and risk assessment for rail projects
T955 - May 2014
Next Steps
A number of key recommendations are included in the final report
and includes:
 Further case studies to test and develop the guidance, and
provide a set of 'template risk arguments' for use by similar
projects.
 Update and maintenance of guidance through the standards
management process.
 Development of the SRM Risk Profiling Tool (or a similar tool) for
application to infrastructure projects.
 Investigation of the development of a railway system generic
hazard list (with a scope wider than rolling stock), linked to
causes and controls (particularly TSIs and other Codes of
Practice), and a structure for storing and communicating this
information.
The Industry Standards Coordination Committee has reviewed the
research findings and recommendations, and has agreed that no
immediate follow on research is required as case studies might be
produced as part of other research projects addressing a particular
industry issue. Those aspects of these recommendations that relate to
the update of the SRM risk profiling tool will be addressed on an
ongoing basis as part of RSSB's core work.
Contact
For more information please contact:
Michael Woods
Head of Operations and Management Research
R&D Programme
RSSB
enquirydesk@rssb.co.uk
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