A Hybrid Local Search Algorithm for the Consistent Periodic Vehicle Routing Problem

Under consideration is some new real-world application of vehicle routing planning ina finite time horizon. Let a company have a set of capacitated vehicles in some depots and servesome set of customers. There is a frequency for each customer which describes how often thecustomer should be visited. Time intervals between two consecutive visits are fixed, but thevisiting schedule is flexible. To obtain some competitive advantage, the company tries to increasethe service quality. To this end, each customer should be visited by one driver only. The goal is tominimize the total length of the vehicle paths over the planning horizon under the frequencyconstraints and driver shift length constraints. We present a mixed-integer linear programmingmodel for this new consistent capacitated vehicle routing problem. To find near optimal solutions,we design the variable neighborhood search metaheuristic with several neighborhood structures.The driver shift length and capacitated constraints are penalized and included into the objectivefunction. Some numerical results for the real test instances are discussed.