Research On The Policy Optimization Of Empty Container Reposition Between Coastal Ports

The imbalance of economy’s development results in the unbalance of trade flow that caused serious imbalance between the supply and demand of empty containers. Empty containers reposition is one of the most important problems for the shipping companies. As a result, it’s very central for every shipping company to organize the flow of empty container effectively and raise the efficiency of empty container allocation.Empty containers reposition has drawn great attention from the scholars and the enterprises, and they proceed homologous research. But now most of the shipping companies still distribute the empty containers with experience. It is necessary and significant to put forward theory, model and method to match the current transportation net’s development. From the angle of the shipping company and using the land empty containers distribution theories for reference, the optimization model is constructed for empty reposition, so that the optimization of routing, quantity and time is available. The contents and innovative points of this paper include:Through studying the procedure of container delivery, the whole systems of empty reposition is assorted of the land-reposition and the sea-reposition. This paper researching the system of sea-reposition which is more complex than land-reposition and emphasize the sea-reposition from the component of this system, the demand and supply of empties. In this paper, we present a flexible destination policy (FDP) against a conventional determined destination policy (DDP) in which the destinations are determined before empty containers are loaded onto vessels on basis of the existing research. The flexible destination policy only specifies the direction of the empty flows, whereas ports of destinations are not determined in advance and empty containers are unloaded from vessels as needed. Furthermore, two mathematics models which can minimize the whole transportation cost are constructed.Then this paper shows that the reposition which troubles shipping company long time can be researched with quantitative analysis and resolve the reposition model with genetic algorithm (GA). Simultaneously, the cost of reposition is analysed with the real example. The comparison between two different empty container repositioning policies shows, when the trades are fairly balanced, DDP slightly outperforms FDP But when the trades are imbalanced, FDP outperforms DDP regardless of distribution types of customer demands.The simulation of the procedure of empty container reposition between coastal ports shows that it is feasible to use GA to research this problem. This method is useful because it can construct model easily and simply, so that it is worth to research further.