Multi-mode Personnel Scheduling in Roll-on/Roll-off Terminals

In Roll-on/Roll-off (RoRo) terminals, the maritime transshipment of vehicles is performed as a pre- and post-processing for maritime transportation with RoRo ships, collectively referred to as RoRo operations. RoRo operations are part of the vehicle distribution in automotive supply chains and the field of Operations Research potentially supports the personnel scheduling in RoRo terminals. During loading and unloading, vehicles roll on and off a ramp to be stowed on the decks of the RoRo ship or to be stored in the parking areas of the RoRo terminal. We focus on loadings and personnel who drive vehicles from the parking areas to the decks. Vehicles stored in the parking areas and planned for loading are grouped into batches. We consider the specific problem where there is a departure time of the RoRo ship that must be adhered to, and there is a shortage of personnel in the RoRo terminal so that it is not possible to load all batches. The multi-mode personnel scheduling is formalized as a Constraint Programming (CP) model and teams represent the personnel, weights represent the priority, and ready times represent the earliest possible start time for the loading of each batch. In a computational study, we find that the CP model outperforms the solution quality of the manual personnel scheduling by a human planner.