Track: Logistics

Abstract

Waste collection and transportation processes are accounted for more than 50% of all total waste management costs then there is an urgency for a waste recycling company to minimize this activities-related total cost by any means. Route optimization in collecting those plastics wastes can be a good solution to addressing the problem. This research focuses on determining waste collection routes for multilayer plastic with the objective function of minimizing total transportation costs. The waste collection problem is modeled as Vehicle Routing Problem (VRP) with a certain capacity and constrained time windows but here the vehicle is allowed to travel multiple times, this model said as the Multi-Trip Multi-period Capacitated Vehicle Routing Problem with Time Windows (MCVRPTW). The model was solved by an exact method using mixed integer linear programming and a metaheuristic approach using the Genetic Algorithm (GA). The results showed that the exact method was able to solve problems on small data instances and required almost 100% higher computation time than of metaheuristic approach. The best GA solution with mutation and crossover rates of 0.75 and 0.1 provides savings of 30.2% compared to the total transportation cost for existing conditions.