Applications of fuzzy faulty tree analysis and expert elicitation for evaluation of risks in LPG refuelling station

• Use of qualitative linguistic values in terms of failure likelihoods.
• Experts judgements are aggregated along with weightage for basic events.
• Fuzzy logic combined with expert elicitation used to generate event failure data.
• Fuzzy FTA assess basic event failure probabilities from expert opinions.
• Fuzzy FTA generates the likelihood of occurrence of the top event.

A method is presented for analysis of reliability of complex engineering systems using information from fault tree analysis and uncertainty/imprecision of data. Fuzzy logic is a mathematical tool to model inaccuracy and uncertainty of the real world and human thinking. The method can address subjective, qualitative, and quantitative uncertainties involving risk analysis. Risk analysis with all the inherent uncertainties is a prime candidate for Fuzzy Logic application. Fuzzy logic combined with expert elicitation is employed in order to deal with vagueness of the data, to effectively generate basic event failure probabilities without reliance on quantitative historical failure data through qualitative data processing.The proposed model is able to quantify the fault tree of LPG refuelling facility in the absence or existence of data. This paper also illustrates the use of importance measures in sensitivity analysis. The result demonstrates that the approach is an apposite for the probabilistic reliability approach when quantitative historical failure data are unavailable. The research results can help professionals to decide whether and where to take preventive or corrective actions and help informed decision-making in the risk management process.