A fuzzified version of the economic production quantity (EPQ) model with backorders and rework for a single-stage system

This paper extends a recent work that investigated a single-stage production-inventory model with reworks and planned backorders by fuzzifying its input parameters. The graded mean integration representation (GMIR) method, a useful and effective defuzzification method, is employed to develop a fuzzified total inventory cost function of model of interest. Triangular and trapezoidal fuzzy numbers are used to examine the developed fuzzy model. Later, the optimal policy, including the batch size, the backordering level and total cost, is determined using the classical approach. Furthermore, the derived optimal policies are tested using arbitrary fuzzy numbers.