Equilibrium Quantities Loaded/Unloaded At Calling Ports For Container Shipping Line Optimization Operation

As the large-size of containerships develops continually and the structure of container shipping lines changes complicatedly, how to design the container shipping network and operate the container liner service scientifically for a better economic benefit has become, to the liner company, the problem that call for immediate solution. Meanwhile, the above problem attracts broad attention from the theoretical circle. The study about shipping network design is mature relatively. At the operational level, there is a lot of study about empty container repositioning and slot allocation respectively; however, there is a lack of study which is from the standpoint of the whole operation process including empty container repositioning and slot allocation. Based on this, this thesis combines the two problems by make a decision on the proper quantities loaded/unloaded at every calling port and explicitly taking into account all opportunity costs caused by repositioning empty containers, leasing extra short-term containers and storing unused owned containers.Firstly, the thesis divides the management of container shipping line into two periods, the design period and the operation period, and analyzes the key work in these two periods. Secondly, based on the above analysis, the thesis summarizes the container shipping line optimization operation problem and analyzes the correlative influence factors. Then, the thesis addresses the relationship between empty container repositioning and slot allocation, and expresses them by the quantities loaded/unloaded at every calling port. Thereby, the model of the container shipping line optimization operation is formulated. After the analysis of the model and prediction of the results, the thesis presents numerical example .The validity of the model is testified and the thesis deduces an important conclusion: for a container shipping line with vessels of same capacity and same cruising speed, under the circumstance of relatively stable market demand, the line will keep equilibrium operation if the quantity loaded is equal to the quantity unloaded at every calling port.