Integrated optimisation of loading schedules and delivery routes

In warehouses, routing decisions for vehicles are highly related to the schedule of docks and loading operations. To mind the gap that most existing studies consider the routing decisions solely, this study investigates the vehicle routing problem with time windows and loading scheduling (VRPTW-LS). In this problem, the loading schedules at the loading docks and the visiting sequences for vehicles are determined to minimise the total travelled distance. To solve this problem, an adaptive large neighbourhood search algorithm, embedded with a tailored solution representation and an efficient feasibility check mechanism, is developed. In addition, the results of extensive computational experiments verify the effectiveness and efficiency of the proposed algorithm, and some analyses are conducted to obtain managerial insights.