Preliminary Hazard Analysis (PHA): New hybrid approach to railway risk analysis
Résumé
The Preliminary hazard analysis (PHA) is used to essentially identify potential accidents related to the system and its interfaces to assess their probability of occurrence and the severity of the damage they may cause and finally propose solutions that will reduce, control or eliminate. Although essential in the process of analysis and safety evaluation of high-risk industrial system, the method PHA is very differently developed and remained unclear. This method is generally classified in theory by an inductive approach. However, in practice, a deductive approach is essentially used as the Fault tree analysis. To enhance the quality of the safety analysis in terms of completeness and consistency, we suggest a new hybrid method that combines these two modes of reasoning: induction and deduction. Indeed, the safety analysis of a complex system requires from experts in the field implementation of an iterative analysis process involving both inductive and deductive approaches. The ambition of this new method is to consolidate and renovate conventional approaches. In addition, this method is based on the use of a standardized vocabulary and a rigorous analytical approach likely to be accepted by all actors who participate in the development of safety documentation. Indeed, in accordance with national and European regulations and in particular the Railway Safety Directive, this paper proposes a generic approach for development assistance, assessment and prevention of risks which takes account of uses, theory and our experience in this domain.