Joint optimization of LORA and spares inventory with fuzzy parameters

Level of repair analysis (LORA) and multi-echelon technique for recoverable item control (METRIC) type methods are widely used to solve the downtime costs of complex equipment. In this paper, a joint optimal model of LORA and spares inventory for cases of fuzzy failure rate is constructed, and fuzzy parameters are implemented to deal with these uncertain factors to make optimal decisions. Taking the best cost-effectiveness ratio as criterion, expected number of backorder (EBO) as objective function and cost as constraint, a multi-echelon, multi-indenture (MEMI) optimization model based on fuzzy sets is built, and a convex optimization algorithm of multi-variable with fuzzy parameters is also proposed. Our provided method is proved to be credible and effective according to the numerical example and simulation result in the paper.