Integrated Liner Shipping Network Design and Scheduling, or: Solving a large service network design problem

Global container liner shipping networks are composed of services and each service represents a roundtrip that connects a set of ports following a published schedule. The majority of services is operated at a weekly frequency, and each port on a service is visited at the same time each week. Commonly, all vessels deployed on a service are of the same capacity. Liner services are connected through common port calls that allow liner network operators to move cargo from one service to another. The movement of containers between services is called transshipment and enables large liner shipping companies to transport containers between almost any possible pair of ports around the globe. Current state-of-the-art models and methods (e.g. Karsten et al., 2017) for liner shipping network design problems only determine the routes and sailing speeds for individual services, but approximate transshipment times by a constant. In practice, the transshipment time between two services depends on how well the schedules of the individual services are synchronized. In the network of the world’s largest overseas cargo carrier, around half of all transported containers are transshipped, and the transshipment times may significantly affect the total transit time of containers between their origin and destination port.