Metastrategy simulated annealing and tabu search algorithms for the vehicle routing problem
Annals of Operations Research - Special issue on Tabu search
Metaheuristics for the capacitated VRP
The vehicle routing problem
The vehicle routing problem
Cost Models for Vehicle Routing Problems
HICSS '02 Proceedings of the 35th Annual Hawaii International Conference on System Sciences (HICSS'02)-Volume 3 - Volume 3
A multi-phase constructive heuristic for the vehicle routing problem with multiple trips
Discrete Applied Mathematics - International symposium on combinatorial optimisation
Efficient Insertion Heuristics for Vehicle Routing and Scheduling Problems
Transportation Science
A Tabu Search Algorithm for the Split Delivery Vehicle Routing Problem
Transportation Science
A variable neighborhood search for the multi-depot vehicle routing problem with loading cost
Expert Systems with Applications: An International Journal
An insertion heuristic manpower scheduling for in-flight catering service application
ICCL'12 Proceedings of the Third international conference on Computational Logistics
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In this paper, we study a new variant of the vehicle routing problem (VRP) with time windows, multi-shift, and overtime. In this problem, a limited fleet of vehicles is used repeatedly to serve demand over a planning horizon of several days. The vehicles usually take long trips and there are significant demands near shift changes. The problem is inspired by a routing problem in healthcare, where the vehicles continuously operate in shifts, and overtime is allowed. We study whether the tradeoff between overtime and other operational costs such as travel cost, regular driver usage, and cost of unmet demands can lead to a more efficient solution. We develop a shift dependent (SD) heuristic that takes overtime into account when constructing routes. We show that the SD algorithm has significant savings in total cost as well as the number of vehicles over constructing the routes independently in each shift, in particular when demands are clustered or non-uniform. Lower bounds are obtained by solving the LP relaxation of the MIP model with specialized cuts. The solution of the SD algorithm on the test problems is within 1.09-1.82 times the optimal solution depending on the time window width, with the smaller time windows providing the tighter bounds.