A discrete-time model for optimizing the rail port cycle

The main objective of this work is to model and optimize the rail cycle in seaport terminals. The model proposed in the paper represents the transfer of import containers from their storage in the yard until their exit from the terminal by train. At this purpose, the standing of containers and their movements inside the terminal are modelled by a set of queues, whose dynamic evolution is described by discrete-time equations, where the state variables represent the queue lengths and the control variables take into account the utilization of terminal resources (handling systems as well as tracks) and the timing of train movements from the terminal towards their destinations. On the basis of this model, an optimization problem is defined that consists in minimizing the transfer delays of containers in the terminal while satisfying specific real constraints. This model has been tested on real data regarding an Italian container terminal, as reported in the paper.