In this paper, a hybrid genetic algorithm is proposed to solve a Capacitated Location-Routing Problem. The objective is to minimize the total cost of the distribution in a network composed of depots and customers, both depots and vehicles have limited capacities, each depot has a homogenous vehicle fleet and customers’ demands are known and must be satisfied. Solving this problem involves makin...

This paper introduces the fleet size and mix location-routing problem with time windows (FSMLRPTW) which extends the location-routing problem by considering a heterogeneous fleet and time windows. The main objective is to minimize the sum of vehicle fixed cost, depot cost and routing cost. We present mixed integer programming formulations, a family of valid inequalities and we develop a powerfu...

In this paper we propose the application of Pareto ant colony optimization (PACO) in solving a bi-objective capacitated vehicle routing problem with route balancing (CVRPRB). The objectives of the problem are minimization of the tour length and balancing the routes. We propose PACO as our response to the deficiency of the Pareto-based local search (P-LS) approach which we also developed to solv...

The solution of the biobjective IRP is rather challenging, even for metaheuristics. We are still lacking a profound understanding of appropriate solution representations and effective neighborhood structures. Clearly, both the delivery volumes and the routing aspects of the alternatives need to be reflected in an encoding, and must be modified when searching by means of local search. Our work c...

In this paper, we investigate the bi-objective multiperiod one-dimensional cutting stock problem that seeks to minimize cost of production associated with total length cut objects (waste) and inventory costs related items. A mathematical model is presented heuristically solved by a column generation method. Computational tests were performed using Weighted Sum method, ε-Constraint method variat...

nowadays, the environmental impact of transportation project and, especially air pollution impacts, are major concerns in evaluating transportation projects. based on this concern, beside definition of traditional objective functions like total travel time and total investment cost, different type of environmental related function is considered as objective function in urban network design. in ...

This paper presents a methodology for solving the Periodic Vehicle Routing Problem (PVRP). Customer locations each with a certain daily demand are known, as well as the capacity of vehicles. In this work, the problem is solved by means of a two-phase heuristic. The first phase is the itinerary assignment to visit each customer, and in the second phase the routing is done for each day of the iti...