Applying a time-space network to reposition reefer containers among major Asian ports

Empty container repositioning is a complicated daily operation that liners have to deal with due to the imbalanced cargo flows. This operation is comprised of two main problems: repositioning both dry containers and special containers. Due to the considerable amount of containers and high similarity, dry containers are usually moved in batches. In addition, leasing and pooling are also complementary strategies commonly used to adjust the allocation of empty dry containers. On the contrary, reefer containers have to be repositioned more precisely than dry containers because they can yield high profits and cannot be substituted easily. This study formulates a time-space model suitable for dealing with this large scale mathematical problem. A comparison between the model output and real operation is made to demonstrate the performance of the proposed model.