Institute of Transportation, MOTC

       In the process of retrieving inbound containers, plenty of container relocation operations are generated due to the discrepancy between the storage position of containers and the retrieving order. Also, the uncertainty of the number and the time period of container trucks arriving at the container port causes the problem of traffic congestion. The two situations above influence the efficiency of container retrieving process and cause additional operation cost. To overcome the container relocation problem, lots of researches have developed different kinds of exact solutions and algorithms to reduce the number of container relocation operation. For solving the container truck congestion problem, some foreign container ports have applied the truck appointment system to control the number and the arrival order of the container trucks in advance and effectively smooth the peak of truck number during different time period.
       This study combines the container relocation problem, the concept of truck appointment time window and the concept of container ship stowage plan from the past research into the model. We propose an inbound container retrieving operation model with considering “container stacking” and “truck appointment time window” and establish a mathematical programming model by referring to the past research literatures. In the mathematical programming model, the costs of both container terminal operator and container truck operator are considered simultaneously to strengthen the effectiveness of coordination and cooperation between the two parties. In addition, there are practical operation restrictions in the mathematical programming model to make the model conform with actual operation situation. By testing small examples and practical data with the mathematical programming model, it is confirmed that this study helps to reduce the operation cost during the process of retrieving inbound containers. Compared with the scenario that the container stowage plan is not considered, the percentage of improvement of this study in the container relocation cost, time period adjustment cost and total operation cost can reach up to 100%, 50% and 81.8%. The results confirm that this study can be used as a reference model for improving the operation of retrieving inbound containers in the future.