Quay length optimization using inventory and stochastic knapsack models

Abstract

Within this study, it is aimed to develop a method to determine the optimal quaylength. Since one of the most significant drawbacks of the maritime transportation isthe delays encountered in ports where loading and unloading takes place, an optimal quay length possesses great importance to reduce the handling time in an efficientmanner. Besides, the larger is the capacity of a port, the higher is the number ofships served and the revenue obtained. Another important issue is that it is veryimportant to avoid unnecessary investment and to reduce the capital cost. Hence, the determination of optimum capacity of a port becomes a very important issue especiallyduring the port planning and design stage. Our goal in this work is to try to solvethis problem by working on a particular subject: Optimum quay length determination.For this purpose, we first propose the use of inventory based models. These are static models and disregard the dynamic nature of the ship arrivals and departures. Wetherefore extended them to also handle this aspect, through dynamic programming.However, these models are also restrictive since they do not consider the stochasticityof ship arrivals. Finally, we propose a method based on the stochastic knapsack model to determine the optimum length of a single quay. For the validation of the model,real data from the ports all over the world are used. The model can also be used todetermine approximately the situations, where there are more than one quay in parallel.Finally, the model is generalized into a scheme so that the optimal quay length can be obtained by just knowing the daily number of ships, average length of ships arriving,and the average handling rate per day.