(84c) Simultaneous Berth and Yard Allocation Planning of Container Vessels at Tactical Level

A reduction in the productivity of port has been observed over the past several years, due to inefficient usage of the available resources. The terminal operator faces the problem of determining berth positions for each of the vessels such that resources can be used as efficiently as possible. One of these resources is the quay, another resource is the yard. Amongst all the operations, the most important is an optimal berth allocation of the ship and yard allocation for the containers. They are inter-dependent on each other and conventional berth allocation and planning models have difficulties to handle the uncertainty of vessel arrival. And terminal operators strive to optimize the berth and yard allocation planning so as to minimize the travel distance of all containers. Because long travel distance not only causes high cost of carriers but also has a potential threat to the loading and discharging operations at the quayside. So, it is crucial to consider these two planning problems in an integrated manner.

To deal with disturbances in transportation schedules, two approaches are getting more and more attention: (i) proactive robustness, which incorporates buffer times into strategic or tactical timetables to deal with disturbances and thus to prevent delay propagation through a well set schedule, and (ii) reactive disruption management, which is concerned with operational recovery after a disruption. The research in this paper focuses on incorporating proactive robustness into the nominal berth and yard planning.

Mathematical optimization has been used to improve the operational capability of port terminals using various realistic constraints. Many papers consider berth planning problems at an operational level. However, only a few papers consider tactical berth planning problems. Furthermore, the simultaneous berth and yard allocation planning problem has rarely been raised, and the associated methodologies have neither been systematically studied. Normally the berth allocation serves as an input for the yard planning problem, and both problems are solved separately. Existing publications are either focused on planning problem without considering realistic flexible arrival and departure time windows or using fixed maximal deviation from nominal arrival time [1].

The goal of this study is to optimally use the resources on the quay. For instance, making the most of quay cranes and minimizing total carrier transportation cost. In this paper, a new time window-based berth and yard allocation planning problem at the tactical level has been developed. Flexible arrival and departure time windows have to be taken into account specifically as control variables. Two different solving strategies: (i) two-stage model, and (ii) simultaneous model are employed to obtain the optimal berthing schedule of each vessel and the optimal schedule of containers transshipment. And the optimization results of these two different solving strategies are presented and compared. Computational results of the case studies demonstrate the efficacy of the developed planning models. Commercial solvers such as CPLEX and ANTIGONE have been employed to obtain the optimal solutions of the developed MIP and MINLP models, respectively.

References

1. Hendriks, M.P.M., E. Lefeber, and J.T. Udding, Simultaneous berth allocation and yard planning at tactical level. OR Spectrum, 2013. 35(2): p. 441-456.