The analysis of risks arising from railway operations has historically focused on the study of technical aspects, but in recent years the human factor has increasingly been dealt with in greater depth in these analyses.
This change is promoted by the new legislative framework on railway safety, and the common safety methods, and introduces the obligation to take them into account and integrate the treatment of human factors into the safety management systems of both infrastructure managers and railway undertakings.
Directive (EU) 2016/798
Through its processes, the safety management system should ensure that human capabilities and limitations and influences on human performance are addressed through the application of human factors knowledge and the use of recognised methods.
This requirement was expanded and further developed in Delegated Regulation 2018/762, on safety management system requirements:
"Human behaviour plays a central role in the safe and efficient operation of railways. It is therefore essential that railway undertakings and infrastructure managers adopt a systematic approach to support human performance and to manage human and organisational factors within the safety management system".
For this purpose, the regulation includes, among others, the following requirements focused on their treatment:
"188.8.131.52 The organisation shall be responsible for:
- Detect and analyse all operational, organisational and technical risks significant to the type, scope and coverage of its own operations, including risks arising from human and organisational factors, such as workload, job characteristics, fatigue, adequacy of procedures, and the activities of other stakeholders (see 1. Organisational context);
- The organisation shall present a systematic approach to integrate human and organisational factors into the safety management system. The approach:
- It will include the development of a strategy and the use of recognised expertise and methods in the field of human and organisational factors;
- Address the risks associated with the design and use of equipment, tasks, working conditions and organisational arrangements, taking into account both human capabilities and limitations, as well as elements influencing human performance".
Through these regulatory requirements, companies in the railway sector are being pushed to increasingly take human factors into account and integrate them into their Safety Management Systems.
In other sectors, such as the aeronautical or nuclear sectors, the integration of human factors in safety management systems and risk analysis has been dealt with for many years and therefore the progress of their integration and experience is a very important source of knowledge to be taken into account. For example, aspects to improve stand out, such as the treatment of human factors in railway maintenance.
The "reglamento" regulates the requirements of entities in charge of railway rolling stock maintenance, but still does not mention the integration of Human and Organisational Factors in the Maintenance Management System (MMS), which contrasts with cases such as aeronautical maintenance, where human factors have been introduced since the late 1980s.
The study of human factors has been developed on the basis of events and accidents whose cause has been attributed to human error (in the national railway sector, accidents such as the Valencia metro accident in 2006 or the Santiago accident in 2013 stand out).
With the significant technical development of recent years, equipment has become increasingly reliable and complex. As a result, the majority of accidents nowadays are no longer caused by technical failures, but by human error.
That is why the big workhorse today is to analyse and prevent these human failures in order to improve the overall safety of the railway system.
If we look at the most recent annual report published by the CIAF (Comisión de Investigación de Accidentes Ferroviarios) concerning the accidents and incidents investigated in 2021, when the cause of the event was attributable to the railway system, the direct cause with the highest incidence was attributed to the human factor (present in 75% of the events) and the remaining 25% was attributed to failures in the installations.
It is clear that it is very important to take Human Factors into account when analysing potential risks and designing operational processes and procedures.
It is not enough to conclude that an accident was caused by human error, it is necessary to study the error and analyse why it occurred and the causes that led to it, in order to understand it and act so that it does not happen again.
In order to make progress on this point at national level, Regulation 929/2020 on Railway Operational Safety and Interoperability includes Human factors in the classification of events and direct causes.
Similarly at European level, Regulation (EU) 2020/572 on the reporting structure for railway accident and incident investigation reports was published in 2020, which gives great importance to the study of human factors.
Human errors cannot always be avoided, but it is very important to identify them, study them and put measures in place to prevent their recurrence. Human beings are a source of error, but also of reliability and the ability to react to potential problems.
Therefore, in the same way that work is being done on technological development and the study of the reliability of components, progress must be made in the development of Human Reliability to minimise the occurrence of errors caused by human beings.
Techniques for defining a study methodology
- THERP (Technique for Human Error Rate Prediction): Tasks are decomposed into elementary activities and their sequence is visualised in an event tree, together with their possible deviations in the form of operator error of omission or commission. The basic event representing human error can be represented as a subset of nodes in the tree so that its probability can be calculated by multiplying the probabilities along the tree. It is widely used for human reliability data in risk probability assessment studies (Swain and Guttman in 1983).
- SHERPA (Systematic Human Error Reduction and Prediction Approach): It is based on functional analysis of human behaviour; it aims to qualitatively and quantitatively assess human reliability and to develop concrete recommendations to reduce the likelihood of human error, especially with regard to procedures, personnel training and equipment design (Embrey, 1986).
- HEART (Human Error Assessment and Reduction Technique). It is a technique for arriving at probabilities of human error by matching the task being assessed to one of nine generic task descriptions from a database and then modifying the probabilities of human error according to the presence of identified error conditions. (Williams, 1988).
- Human Hazop: It consists of structured brainstorming involving experts from different areas (operation, project planning, risk management, human factors experts, etc.). Guiding words are used and meetings are structured with the aim of identifying threats due to human error.
- SHELL Model: This model not only takes into account the different component parts in isolation, but pays special attention to the interfaces of the human element with the different elements of the system.
- GEMS (Generic Error Modelling System): The GEMS model distinguishes between errors as such made without intent, and infringements where the operator is aware that his actions deviate from the norm.
In the railway sector, Human and Organisational Factors have traditionally been considered only in the areas of driving and traffic management.
However, it is important to analyse the risks associated with the human factor at the different levels of the organisation and the different profiles with responsibilities that affect security.
In this sense, the knowledge of the staff involved and leading in the daily operation should be studied in relation to the integration of the Human Factor.
Also the impact of these concepts on staff behaviours and the willingness to learn and to change certain behaviours that may not be appropriate.
To achieve this, it is of vital importance to lead and promote these analyses, and the changes derived from their results, from the top management of companies. To this end, training in Human Factors at all levels of the company is vital.
It is clear from the above that there is still a lot of work to be done in the railway sector to ensure that human factors are properly integrated and taken into account in risk analysis, accident investigation and organisational and operational processes of railway undertakings.
This is illustrated by the fact that the common safety method (Regulation (EU) No 402/2013 on the adoption of a common safety method for risk evaluation and assessment) is rarely applied to the management of risks associated with organisational changes and, in the few cases in which it is actually applied, it is rare for these changes to be considered significant.
Similarly, if we analyse the majority of technical or operational change files, we find that risks associated with human factors are rarely identified, assessed and managed.
Training in the application of this regulation and specifically in the integration into the analysis and management of risks arising from human factors is of great importance.
To this end, Exceltic offers customised courses for risk analysis training and the implementation of Regulation (EU) No 402/2013, which provide an introduction to the legal and regulatory framework and guide the need to establish a methodology to carry out an adequate and comprehensive risk management, taking into account both technical, operational and human factors.