Lot sizing and pricing problem in a recovery system with returns and one-way substitution option: Novel cost benefit evaluation based approaches

International audienceIn this study, we investigate the joint pricing and lot-sizing problem in a hybrid manufacturing and remanufacturing system with one-way substitution option. The objective is to find the optimal prices and quantities over each period that maximizes the firm revenue, minimizes holding and production costs, and meets the customers’ demands. The considered system is a single production line where both operations of manufacturing and remanufacturing are hold. The items issued from the two processes are not of the same quality and price. The remanufacturing option is based on the collected used products called returns and generates products with less quality. In this paper two demand yields are considered, for new and remanufactured items. In the shortage case of remanufactured items, a one-way substitution option is assumed, so that the demand of these remanufactured items is satisfied by new ones. The objective is to find the optimal prices and quantities in each period that maximizes the firm revenue. The paper proposes a mixed integer-programming model to find optimal production and pricing strategy over a planning horizon, a novel adaptation of cost benefit evaluation heuristic and a memetic algorithm to find near optimal solutions. An extensive simulation analysis is performed for different values to confirm the performance of the proposed approaches

Path Relinking for a Constrained Simulation-Optimization Team Scheduling Problem Arising in Hydroinformatics

We apply Path Relinking to a real life constrained optimization problem concerning the scheduling of technicians due to activate on site devices located on a water distribution network in case of a contamination event, in order to reduce the amount of consumed contaminated water. Teams travel on the road network when moving from one device to the next, as in the Multiple Traveling Salesperson Problem. The objective, however, is not minimizing travel time but the minimization of consumed contaminated water. This is computed through a computationally demanding simulation given the devices activation times. We propose alternative Path Relinking search strategies exploiting time-based and precedence-based neighborhoods, and evaluate the improvement gained by coupling Path Relinking with state of the art, previously developed, hybrid Genetic Algorithms. Experimental results on a real network are provided to support the efficacy of the methodology