Optimization of multi-product EPQ model with defective items, reworks, and constrained number of orders

In this paper, a bi-objective multi products EPQ model has been developed. In this case, there are some imperfect items which are reworkable while the numbers of orders are restricted. A problem, as a multi objective nonlinear programming model, is modeled and the non-dominated sorting in genetic algorithm (NSGA-II) and multi objective particle swarm optimization (MOPSO) algorithms are recommended to solve it. To demonstrate the performance of proposed algorithms, some comparison criteria are applied and Simple Additive Weighting (SAW) method is employed to evaluate best algorithms