A new structure of performance shaping factors for human reliability in railway applications

Kurzfassung

Human factors do not yet have a long tradition in the railway context. Ergonomics and safety aspects have led to a special interest in human factors in the European railway domain since about the turn of the century. It has been understood that human performance contributes to the performance and safety of the railway system. Furthermore, in risk assessments, data for human reliability is needed. In order to enable an overview on human factors in railway applications this contribution provides an integrated model covering the working systems of train drivers and signallers. The model encompasses the physical, personal and organisational aspects of work and distinguishes between independent influence factors and dependent variables. Beside rather static influencing factors, the working system is also shown in the moment of operation, with dynamically changing inputs. When the objectives for human factors engineering are added, the model visualizes chains of actions, for example how an improvement of training can affect safety in the end. The elaboration of a well-structured set of performance shaping factors is shown. This analysis contributes to a new approach to assess human error probabilities. In the railways, human reliability assessment (HRA) is not yet common, but in risk assessments, the integration of human performance is evident. Existing HRA techniques date back to other applications and are very complex to conduct. It is briefly discussed whether the methods can be used in railway contexts when they do not account for particularities in the working systems of train drivers and signallers. A step on the way to a convenient method for railway practitioners is made with the new approach.