An Optimization Model for Tramp Ship Scheduling considering Time Window and Seaport Operation Delay Factors

Abstract

The quantity of electrical coal transported through the tramp shipping network is increasing due to the high demands. This trend has increased the scheduling difficulty combined with the underdevelopment of the private thermal power plant port. The high coal consumption and low port storage capacity requires the scheduling of the tramp ship to be on a strict time window to ensure the continuous operation of the thermal power plant. The low port unloading capacity often leads to the port congestion and delay of the unloading operation. This paper develops a mixed-integer-programming model for the optimization of the tramp ship scheduling to reduce the total operation cost, including the transportation cost and the unloading waiting cost, and the branch-and-price algorithm is adopted to solve this large-scale model. The model and algorithm are tested with historical operation data from the thermal power plant in the southern coastal areas of China. The optimized scheme significantly reduces the total operation cost by reducing the unloading waiting time and the number of active vessels in certain periods. The results also demonstrate the algorithm improvement in the aspects of the optimization quality and efficiency comparing with the heuristic solution.

Integrated Inbound and Outbound Scheduling for Coal Port: Constraint Programming and Adaptive Local Search

“…Gao et al [13] described the unloading scheduling problem of a bulk cargo terminal in a large steel plant as a flexible shop scheduling problem, established a corresponding mixed-integer programming model, and proposed a column generation method to solve the optimization model. Yang et al [21] formulated a mixed-integer programming model for scheduling irregular ships in coal ports and utilized the branch pricing algorithm to optimize the scheduling of such ships. Li et al [22] formulated a multi-objective optimization model that considers multiple traffic constraints for the ship traffic scheduling problem of a shared navigation channel in the context of coal ports.…”

Solving fuzzy dynamic ship routing and scheduling problem through new genetic algorithm

“…Our second research motive is the facilitating the transport of cargo whose demand and supply are determined dynamically. Yang et al (2021) designed a tramp ship routing model to address port congestion because of static demand and supply. The result revealed that dynamic demand and supply reduce port congestion and render the system robust.…”