Unmanned aerial vehicle and autonomous delivery robot station for last-mile delivery services

Innovation in the logistics industry has been steadily drawing attention to meet customer and company needs. Delivery services using unmanned aerial vehicles and delivery robots, as next generation delivery vehicles, have been actively investigated in both academia and industry. This paper introduces the new last-mile delivery station model that considers two practical issues. First, to hedge business risks (i.e. delivery suspension or inefficient routing) that can arise when employing homogeneous vehicles, companies are likely to adopt heterogeneous vehicles for their delivery service models. Only homogeneous vehicles are used in existing station models. Second, this study sets the weighted sum of costs and makespan as the objective function and explores the trade-off between the two measures. No previous studies consider the costs and makespan at the same time. A mathematical formulation is developed and a tailored heuristic algorithm is proposed to solve large-scale problems. To observe the proposed model in depth and verify the performance of the heuristic algorithm, numerous computational experiments are conducted for randomly generated instances. Sensitivity analyses are performed to derive managerial implications by manipulating key factors that may affect the performance of the model.