A robust branch‐cut‐and‐price algorithm for the heterogeneous fleet vehicle routing problem

This article presents a robust branch‐cut‐and‐price algorithm for the heterogeneous fleet vehicle routing problem (HFVRP), vehicles may have distinct capacities and costs. The columns in the formulation are associated to q ‐routes, a relaxation of capacitated elementary routes that makes the pricing problem solvable in pseudopolynomial time. Powerful new families of cuts are also proposed, which are expressed over a very large set of variables. Those cuts do not increase the complexity of the pricing subproblem. Experiments are reported where instances with up to 75 vertices were solved to optimality, a major improvement with respect to previous algorithms.