A genetic algorithm approach to optimize a multi-products EPQ model with discrete delivery orders and constrained space

The economic production quantity (EPQ) is one of the most applicable model in production and inventory control environments. Like other classical production and inventory control models, it is derived based upon assumptions that cause limited real-world applications. Continuous and constant-rate delivery of orders, infinite availability of warehouse spaces, and applicability on a single product are some of these assumptions. In order to make the EPQ model more applicable to real-world production and inventory control problems, in this paper, we expand this model by assuming that the orders may be delivered discretely in the form multiple pallets. In addition, we may have more than one product along with warehouse space limitation. Under these conditions, we formulate the problem as a non-linear integer-programming model and propose a genetic algorithm to solve it. At the end, we present a numerical example to demonstrate the application of the proposed methodology.