Quantitative OHS evaluation : RATE procedure compared with traditional reliability methodologies

The most careful and consolidated risk analysis methods, as FTA, ETA, FMEA/FMECA, focus attention on system reliability. But, looking at OHS, a deep analysis on European data on accidents at work and on work environment in general, shows how reliability is only one aspect of safety problem. These methods then are hardly adaptable when the main aim is to obtain a quantitative assessment of risk for workers; besides, Rother methodologies are nearest to OHS but give only qualitative results like HAZOP, or base their analysis on notdimensional values, fixed by analyst on personal experiences, like methods proposed by UNI EN 1050, by standard MIL-STD-882c and by AISS. RATE is proposed as a new quantitative methodology for OHS, particularly dedicated to SMEs considered as the most interesting from these aspect. The paper compares hypothesis and procedures which traditional quantitative methodologies and RATE are based on, to give evidence at the main approach aspects that have to be modified in order to move from reliability to OHS.