5. Conclusions and future work
This paper has proposed two collaborative mechanisms between container shipping lines and port operators to facilitate port operators to make more efficient and equitable tactical berth allocation decisions. In the first mechanism, a shipping line needs to provide the utilities associated with the start operation days of a week at the port for liner service routes with no transshipment containers, where a higher bunker and inventory cost means a lower utility. The port operator compensates the shipping line if its ship is scheduled on a day with negative utility and charges additional fees if the ship is scheduled on a day with positive utility. The requirement that the sum of the utilities of a week equals 0 ensures that the mechanism is fair to shipping lines and port operators, and ensures that shipping lines have no incentive to overstate or undervalue the utilities. In the second mechanism, a shipping line needs to provide the utilities associated with the difference of the start operation days of two liner routes with transshipment containers, where the utilities are related to the inventory cost of the transshipment containers. It is easy to understand that the utilities estimated by shipping lines should be much more accurate than those estimated by port operators. Moreover, utilities estimated by shipping lines reflect the perceived service quality of the shipping lines. The resulting tactical berth allocation model incorporating the utilities provided by shipping lines under the collaborative mechanisms leads to more efficient and equitable berth allocation plans. The utilities provided by shipping lines can also guide the decisions on the operational berth allocation problems.
