Risk Assessment of Lift-Jacking Accidents Using FFTA-FMEA

Lift-jacking accidents are one of the five common accidents in the lift field, characterised as a high hazard. In addition, it is difficult to obtain absolute probabilities of risk factors for lift accidents which are ambiguous and uncertain. In order to solve related problems and perform a comprehensive risk assessment of lift-jacking accidents, a risk assessment methodology integrated with FFTA (Fuzzy Fault Tree Analysis) and FMEA (Failure Mode and Effects Analysis) has been proposed. First, qualitative analysis of the fault tree was applied to identify risk factors of TE (Top Event). Then, a hybrid approach for the fuzzy set theory and weight analysis was investigated to quantify the probability of every BE (Bottom Event), and quantitative analysis was conducted. Finally, an analytical model was constructed by linking FFTA and FMEA through indicator conversion, which leads to overall risk evaluation. An application on a real project example shows that (1) the FFTA-FMEA model can aggregate expert assessment opinions and effectively eliminate ambiguity and uncertainty of risk factors of lift-jacking accidents. (2) The FFTA-FMEA model can quantify the risk of lift-jacking accidents and identify medium to high-risk factors in a multi-angle, deeper, and precise level. The method offers a theoretical framework for the development of preventive measures and safety management strategies for lift-jacking accidents. The practical application in reliability engineering demonstrates its convenience and efficiency, indicating its significant value in this field.