Sustainable fuzzy inventory for concurrent fabrication and material depletion modeling with random substandard items

This study aims to develop a fuzzy inventory model for sustainable concurrent fabrication and material depletion model with randomly selected substandard items. An Economic Production Quantity (EPQ) model was developed using a single-valued neutrosophic number. Substandard items were modeled as random variables. To determine the optimal production strategy, the model was solved numerically using Python’s SciPy library to obtain the production quantity, amount of fabrication, capacity of vehicle, fabrication period, depletion period, preventive measures, duration of vehicle and the total cost. The models parameters were estimated using relevant historical data and industry reports. During the fabrication period the demand is uncertain a single-valued triangular neutrosophic number, Fb = (5,980, 6000, 6500); 0.98, 0.04, 0.03 is used to handle uncertain demand and defuzzification is used to demonstrate the crisp value of demand. A numerical example solved with Python shows a total cost of $235,271.60, offering important insights into the model’s economic implications.