Application of an improved bowtie method in a CMS-compliant risk assessment of a change introduced in the EU railway system

The issue of managing the risk associated with introducing changes to the railway system is very important from the point of view of safety management, as any change can significantly reduce the level of safety of a railway system. For this reason, such changes are regulated at the European Union (EU) level through a dedicated legal act known as the Common Safety Method for risk assessment (CSM). The example presented in this paper is a portion of the analysis carried out for an Estonian freight carrier with a bowtie method, which we improved so that it fully complies with the CSM requirements. This analysis concerns a change consisting of allowing the possibility of a freight train being driven by one person (with no assistant driver). The case study presented in the paper, although limited due to confidentially issues, allows a full description of how to use the proposed method in real-world applications.