The Container Shipping Network Design under Changing Demand and Freight Rates

This paper studies the optimization of container shipping network structures and its operations under changing cargo demand and freight rates. Most existing studies that use a given matrix of average demand have not been able to deal with practical issues such as empty container repositioning, ship-slot allocating, ship sizing, and container configuration. In this paper, these issues are simultaneously considered based on a series of matrices of demand in a year. The problem is formulated as a mixed integer non-linear programming problem (MINP) with an objective of maximizing the average unit ship-slot profit in three stages by using analytical methodology. A genetic algorithm based on heuristic is utilized to arrive at solutions. Through empirical experiments and comparisons, results show that the proposed model can provide a more realistic solution to the issues on the basis of changing demand and freight rates; the model provides a more effective approach to the optimization of container shipping network structures and operations than does a model based on average demand.