Container Liner Operation Economic Model and the Departure Interval Decision-making

To seek the optimal departure interval of container liner operation and related decision variables and find a more economic way for the shipping industry with capital intensive nature, this paper proposes a liner operation economic model. The object is maximal profit from some liner route in a certain operation period and the restrictions are ship load capacity, container quantity of each type and port efficiency of loading and unloading. Based on the container quantity relations among ports on the line, the paper thoroughly analyzes the ship capital cost, operation cost, and voyage variable cost including fuel cost, cargo handling fee, berthing fee, port charges and crew subsidy. It puts forward the harmonic mean method to calculate integrated handling efficiency of different container types at port. And it works out the solution of profit-speed with the conditions keeping a certain amount of fuel on each voyage section and realizes profit at the time of delivery, thus realizing the consideration of maximizing both daily profit of each voyage section and the total operating profit. It then gets the optimal solution of the decision-making variable by combining implicit function derivation and extreme value solving method of functions, and shows the effectiveness of the model via an example.