The Online Distribution System of Inventory-Routing Problem with Simultaneous Deliveries and Returns Concerning CO2Emission Cost

This study attempts to consider CO(2)emission cost to propose an online distribution system of inventory-routing problem with simultaneous deliveries and returns (IRPSDRCO2). The proposed IRPSDRCO(2)mathematical models will be developed to find the total inventory routing cost, the CO(2)emission cost, the optimal delivery routes, the economic order quantities, the optimal reordering points, the optimal service levels, the optimal common review interval, and the optimal maximum inventory levels for all retail stores delivered in these scheduled routes. The proposed IRPSDRCO(2)model further applies the savings method, the target insert heuristic method, the target exchange heuristic method, and the repeated target heuristic method to find the optimal solution and the related scheduled routing plan. The sensitivity analyses will be conducted for this proposed IRPSDRCO(2)model based on different parameters to provide very helpful decision-making information for a distribution system design. The performance of the proposed repeated target heuristic method is demonstrated to be better than most of four other combination methods regarding both the inventory routing cost and CPU running time. Consequently, it should be very helpful for logistics firms to design their distribution system by following the structure and the detailed procedure flow of the online distribution system developed by this study.