Assessment of risks from technical systems: integrating fuzzy logic into the Zurich Hazard Analysis method
In performing a classical hazard or risk analysis of an industrial plant, problems arise in integrating all hazards into an overall risk statement. The Zurich Hazard Analysis (ZHA) is a basic and practical tool to catalogue hazards and represent the corresponding risks by classifications of frequency and consequence of an (undesired) event in a risk matrix format. In extension, fuzzy logic makes it possible to generalize such strict classification schemes in order to consider different measurements, opinions, etc. Integration of fuzzy sets into the ZHA produces a linguistic overall plant risk indicator statement, including all or the most of important hazards. The procedures of computing are shown in a distinct number of working steps and discussed on the basis of practical ZHA case studies.
Keywords: fuzzy logic, hazard analysis, industrial plants, risk assessment, Zurich Hazard Analysis, ZHA, risk matrix, fuzzy sets, plant risk indicators, risk statement