This paper presented a methodology, named as confidence interval based lambda-tau, for analyzing the behavior of complex repairable industrial systems by utilizing vague, uncertain and imprecise data. In this, uncertainties in the data related to each component of the system are estimated with the help of fuzzy and statistical methodology. Triangular fuzzy numbers are used for this purpose as it allows expert opinions, operating conditions, uncertainty and imprecision in reliability information. Various reliability parameters are addressed for analyzing the behavior of the system and their correspondingly obtained results of the proposed approach are compared with the existing fuzzy lambda-tau technique results. The sensitivity as well as performance analysis has also been performed to explore the effect of failure/repair rates of the components on system availability. The approach has been illustrated with an example of synthesis unit of a urea fertilizer plant situated in Northern part of India. The obtained results may be helpful for the plant personnel for analyzing the systems’ behavior and to improve their performance by adopting suitable maintenance strategies.
Uncertain system Fuzzy reliability Lambda-tau methodology Fertilizer plant Confidence interval
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