Multi-period vehicle routing and crew scheduling with outsourcing options

The planning problems confronting logistics service providers frequently involve complex decisions. Motivated by a real-life case study, this paper considers short-range weekly planning on the part of postal companies that must decide about pickup tours and delivery tours for fluctuating volume (number of shipments), with time windows for the demand points, in consideration of variable vehicle capacities and personnel planning, and including outsourcing decisions for tours and drivers. This problem can be formulated as a model of combined tour and personnel planning. However, because a real formulation of the problem involves hundreds of millions of variables and numerous constraints, in practice only heuristic solutions prove relevant. This paper proposes a hybrid metaheuristic combined with a construction heuristic that--as computer simulations have demonstrated--are suitable for practice.