Title: Applying PSO and DE on Multi–Item Inventory Problem with Supplier Selection

We apply Particle Swarm Optimization (PSO) and Differential Evolution (DE) on a multi–item inventory optimization model with supplier selection, limited capacity and defective items. The model assumes an individual cost per transaction as well as a product–dependent holding cost. The goal is the determination of an optimal procurement strategy given the demand over a finite planning horizon. This is formulated as a highly–constrained mixed–integer optimization problem, which is solved using PSO and DE. In addition, the original mixed–integer model is reduced to a real–parameter optimization task and solved with the same algorithms. The results for both approaches are reported and statistically analyzed, offering useful insight regarding the most promising setting.