the models

The key EE&CS assets were first classified into a three-tier hierarchy comprising Category, Form and Type. Category refers to the highest level functions delivered by a system, Form represents the technological variation for delivering the function, and type was intended to identify the exact commercial product employed on the infrastructure.  Where-ever possible, analysis has been carried at the level of Types of equipment and where specific details were not available, form has been the basis for the analysis.

For each item of infrastructure assets, two key aspects have been analysed, often with the aid of the manufacturers and Railtrack maintainers and Zones. The first aspect relates to the composition and architecture of each asset and its fundamental failure modes. This is referred to as Causal Analysis and is mainly concerned with estimation of failure frequencies in each mode and potential unavailability of the equipment in an operational environment, taking into account design, maintenance and operational faults and failures.

The second aspect of analysis relates to capturing the best expert knowledge about the potential escalation scenarios associated with each failure mode, and forecasting the likely range of accidents and incidents which are likely to arise from failed or malfunctioning infrastructure systems and equipment. This is referred to as Consequence Analysis and culminates in prediction of events and their probability/frequencies arising from each failure mode of an asset within an operational context.

The Causal and Consequence modelling has been carried out by competent domain experts in accordance with a strict process and template devised by Railtrack Systems and Safety. For each asset, a Technical Dossier comprising Causal and Consequence analyses was produced with the aim of producing a systematic and best practice knowledge base for the infrastructure assets. These have been in existence since 1997 and have been shared with many railway stakeholders within the UK and the continental Europe. Whilst these dossiers are intended to capture the best available knowledge and state of practice, they are not guaranteed or endorsed as structurally perfect or accurate. Instead, the aim has been to encourage continual improvement and enhancements through usage and feedback by stakeholders.

Access to the models and reports, both causal and consequence, for each of the IRM items has been facilitated in this compilation. The IRM items have been categorised within one of the three following infrastructure asset disciplines. Selection of an infrastructure discipline will enable the selection of relevant IRM items. Selection of a particular IRM item will prompt the user to choose between the causal and consequence analysis.

Click on the appropriate graphic to access the models for the relevant section below: 

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