Container Liner Schedule Design Optimization Based On Modified Steepest Decent Method

With the vigorous development of container transportation and the world maritime industry, the competition of ocean container liner market becomes increasingly fierce. The space of freight growth is limited. The trade imbalance leads to huge loss on empty container allocation. Under such conditions, liner shipping companies are seeking to set appropriate routes and shipment schedule, so that they can increase the benefit-cost ratio and maximize the revenue. Commodity demand produces trade, trade produces transportation. Liner shipping companies set up the route on the basis of considering the transport demand. Based on the established route, this paper is manly on how to adjust the allocation of suitable shipping schedule to minimize the cost.This article analyzes the relationship between shipping schedule, its affecting factors and the operating profitability. The corresponding schedule optimization model is established and the relationship between variables is derived. The ultimate model is a nonlinear optimization with minimized fuel costs and penalties as the objective function and the allocation of each course as the variables. This paper uses a mixed method of steepest descent method and golden section method to solve the model. With the example of a Europe-Far East container liner routes of vessel ’SKAGEN MAERSK’, this paper uses the above method to check the model and analyze the results.From the case study the final conclusion is showed as below. The model under the condition of the high delay penalties will have better optimization results, which can save more than16% of fuel costs and penalties. When port delay and high penalty is taken into consideration, wider range of port delay will lead to more optimal voyage time for the short distance. But comparatively long distance shows the opposite. In this paper, the research results and the established schedule optimization model have certain guiding significance to formulate reasonable schedule and improve economic efficiency for liner shipping companies.