RSSB2422 - T1121 - Development of a Common Event Risk Scoring Methodology

In safety critical industries where accidents are rare events, but can have very serious consequences, it is necessary to gather information about incidents that provide insight into threat levels and the performance of risk controls. Such incidents often do not lead to any actual safety loss but had the potential to escalate into something more serious (such as precursors or Close Calls).

There are many such incident types for which no event risk scoring system exists, creating challenges in identifying those on which investigation and other effort should be focussed, to monitor changes in risk over time, and undertake objective and consistent comparisons between risk areas. These incidents, which occur much more frequently than accidents, may indicate critical areas for improvement in safety management before accidents occur.

Currently the industry has several event risk scoring methods, each designed for a specific event type. For example, the SPAD Risk Ranking method is applied to each SPAD to produce an event risk score. Network Rail uses a methodology to rank incidents in their Signalling Incident Database (SINCS). Network Rail also has a methodology for risk ranking operating incidents, covering a wide variety of different event types.

Until recently, comparison between scores produced by different methods was not possible. Network Rail has now developed The Common Risk Scoring Matrix for Safety (CRSM4S), which places pre and post event risk scores on a common scale. However, many incident types have no event scoring system.

The aim of this project is to develop a common method for assessing these events, acts, and conditions, and ascribing an associated risk score to each. Applying a common risk ranking methodology to these precursors will enable better informed decisions about safety investment. This methodology needs to be compatible with CRSM4S.

The intention of the project is to create a generic methodology that can potentially be applied to any safety-related event. However it is not the intention at this stage (and so outside the scope of the project) to replace existing methodologies for risk-scoring specific types of incidents, such as the SPAD Risk Ranking Tool.

The overall objective is to develop the methodology for a common risk scoring system.

It is anticipated that the method will be incorporated into SMIS+ and will be used by TOCs to enable risks to be assessed against a common scale to support better decision making on the allocation of resource against risks.

The work will be completed into one work package; WP1. It is expected that during the work package there will be ongoing engagement with the project steering group, and will undertake appropriate reporting and presentation of findings to relevant working groups.