A novel mathematical model for a multi-period, multi-product optimal ordering problem considering expiry dates in a FEFO system

• A multi-product multi-period replenishment policy in a FEFO system is studied.
• The inventories of products are assumed to expire at a predetermined date.
• A shared capacitated warehouse is considered.
• A linear mixed integer model is proposed to minimize total costs including disposal.
• Two metaheuristics are developed. The design parameters are set by applying the Taguchi method.

One of the main challenges of retail units is to determine the order quantities of different types of products, each with a specific expiry date, so that the system cost including shortage cost is minimized. We study a new multi-product multi-period replenishment problem for a First Expired-First Out (FEFO) based warehouse management system. The proposed nonlinear model is first converted to a linear one and then solved by applying two evolutionary algorithms: the Genetic Algorithm (GA) and Particle Swarm Optimization (PSO), in which design parameters are set using Taguchi method. Computational results demonstrate the applicability of the proposed model for perishable items and comparing the results shows the efficiency of the proposed metaheuristics as well.