Mohamed Reghioui

GRASP with Path Relinking for the Capacitated Arc Routing Problem with Time Windows

A greedy randomized adaptive search procedure with path relinking is presented for the capacitated arc routing problem with time windows. Contrary to the vehicle routing problem with time windows, this problem received little attention. Numerical experiments indicate that the proposed metaheuristic is competitive with the best published algorithms: on a set of 24 instances, it reaches the optimum 17 times and improves the best-known solution 5 times, including 4 new optima.

A memetic algorithm for the vehicle routing problem with time windows

This article deals with the vehicle routing problem with time windows (VRPTW). This problem consists in determining a least-cost set of trips to serve customers during specific time windows. The proposed solution method is a memetic algorithm (MA), a genetic algorithm hybridised with a local search. Contrary to most papers on the VRPTW, which minimize first the number of vehicles, our method is also able to minimize the total distance travelled. The results on 56 classical instances are compared to those of the best metaheuristics. The efficiency of the MA is similar for the classical criterion, but it becomes the best algorithm available for the total distance, being much faster and improving 20 best-known solutions.

Tour splitting algorithms for vehicle routing problems

Tour splitting heuristics for capacitated vehicle routing problems build one giant tour visiting all customers and split this tour into capacity-feasible vehicle trips. They are seldom used alone because of a reputation of limited performance. This paper describes how to improve them to obtain better solutions or tackle additional constraints. Numerical tests on the capacitated arc routing problem (CARP) and the capacitated vehicle routing problem (CVRP) show that randomized versions outperform classical constructive heuristics. A greedy randomized adaptive search procedure (GRASP) and an iterated local search (ILS) based on these principles even compete with published metaheuristics, while being faster and simpler.

An effective memetic algorithm with population management for the split delivery vehicle routing problem

This paper studies the Split Delivery Vehicle Routing problem (SDVRP), a variant of the VRP in which multiple visits to customers are allowed. This NP-hard problem is solved by a recent metaheuristic called Memetic Algorithm with Population Management or MA|PM (Sorensen, 2003). It consists in a genetic algorithm, combined with a local search procedure for intensification and a distance measure to control population diversity. Special moves dedicated to split deliveries are introduced in the local search. This solution approach is evaluated and compared with the tabu search algorithm of Archetti et al. (2006) and with lower bounds designed by Belenguer et al. (2000). Our method outperforms the tabu search both in solution quality and running time. On a set of 49 instances, it improves the best-known solution 32 times. The savings obtained confirm the interest and the power of the MA|PM.

Split-Delivery Capacitated Arc-Routing Problem: Lower Bound and Metaheuristic

This paper proposes lower and upper bounds for the split-delivery capacitated arc-routing problem (SDCARP), a variant of the capacitated arc-routing problem in which an edge can be serviced by several vehicles. Recent papers on related problems in node routing have shown that this policy can bring significant savings. It is also more realistic in applications such as urban refuse collection, where a vehicle can become full in the middle of a street segment. This work presents the first lower bound for the SDCARP, computed with a cutting plane algorithm and an evolutionary local search reinforced by a multistart procedure and a variable neighborhood descent. Tests on 126 instances show that the new metaheuristic outperforms on average a published memetic algorithm; achieves small deviations to the lower bound; and finds 44 optima, including 10 new ones.

An Evolutionary Algorithm with Distance Measure for the Split Delivery Capacitated Arc Routing Problem

This chapter deals with the Split Delivery Capacitated Arc Routing Problem or SDCARP. Contrary to the classical Capacitated Arc Routing Problem or CARP, an edge may be serviced by more than one vehicle. An integer linear program, an insertion heuristic and a memetic algorithm with population management are proposed for this problem seldom studied. The algorithm calls an effective local search procedure, which contains new moves able to split demands. Compared to one of the best metaheuristics for the CARP, we show that splitting demands can bring important savings and reduce significantly the number of required vehicles.

Memetic Algorithm for two-dimensional loading capacitated vehicle routing problem with time windows

This work concerns the two-dimensional loading capacitated vehicle routing problem with time windows (2L-CVRPTW). A Memetic Algorithm (MA) is proposed to solve this new problem which combines two NP-hard problems : the two-dimensional packing problem and the vehicle routing problem with time windows. The MA presented in this paper considers the unrestricted case for the packing problem. The quality and the efficiency of the proposed metaheuristic is evaluated using test problems derived from the ones designed by Iori et al. [9] for the case without time windows.

Hybrid manufacturing/remanufacturing lot-sizing and supplier selection with returns, under carbon emission constraint

This paper addresses a lot-sizing problem in manufacturing/remanufacturing systems. The studied system is a single manufacturing line where both regular manufacturing and returns remanufacturing processes are carried out, with different set-up costs for each process. We consider also a returns collection phase from customers/distributors with deterministic returns quantities at each period of the planning horizon. The environmental aspect is assumed in this study by considering a carbon emission constraint for the manufacturing, remanufacturing and transportation activities. A mixed integer programming model to minimise the management cost and meet the customer’s needs under different manufacturing constraints is proposed. Otherwise, An adaptation of the well-known Silver and Meal (SM) heuristic and two hybrid method approaches (HM1 and HM2) providing approximates solutions are developed. The mixed integer model was tested on Cplex (Software optimizer), and the obtained results were compared with the ones provided by the adapted heuristic SM and the hybrid methods. The numerical analyses show that hybrid methods provide good-quality solutions in a moderate computational time. The proposed model establishes a collegial and an integrated process that sets values, goals, decisions and priorities along the considered supply chain while taking into account the environmental aspect.

Heuristics for Two-Dimensional Loading Capacitated Vehicle Routing Problem with Time Windows

Abstract This work concerns the two-dimensional loading capacitated vehicle routing problem with time windows. We present for this problem two heuristics. The first one combines an adaptation of the constructive algorithm of Alvarez-Valdes et al. and the famous insertion heuristic of Solomon. The second heuristic uses the touching perimeter algorithm of Lodi et al. and the heuristic of Solomon. There exist two variants of the problem : unrestricted and sequential. We are interested in the unrestricted case, which is known to be NP-hard. To test the quality and the efficiency of the proposed heuristics, some test problems were created based on Iori et al. test problems. Preliminary results are presented and the two methods are compared.