(373ar) Simultaneous Berth and Yard Allocation Planning of Container Vessels for Port Throughput Maximization

Authors: 
Xu, J., Lamar University
Ho, T. C., Lamar University
Xu, Q., Lamar University
To improve the management of container-vessel oriented ports, berth allocation of vessels and yard allocation of containers should be simultaneously modeled and optimized. Such that, various port resources like quay length, yard blocks, quay cranes, and container carriers could be efficiently utilized. Both the yard planning and the berth allocation planning heavily depend on each other. Meanwhile, conventional berth allocation and planning models have difficulties to handle the vessel arrival uncertainty. Once a vessel arrived late, terminal operators may have to revise the current schedule, but the frequent revision of plans is undesirable from a port operation perspective, as frequent revision has an unintended impact on personnel and resource schedules. Mathematical optimization has been used to improve the operational capability of port terminals using various realistic constraints. But existing publications are either focused on planning problem without considering flexible time windows or solving the berth and yard allocation planning problems sequentially and separately.

Most of the customers (i.e., vessel owners) expect prompt berthing upon arrival and early leaving upon finish of their vessels. To minimize the total transporting cost (in the former problem), the berthing location should ideally be selected close to the storage location of the containers and that most of the vessels will be allocated berthing space close to their preferred locations within the terminal. However, to minimize the total handling time of all vessels, all the available quay cranes should be utilized, the berthing location should ideally be selected according to the quay cranes capacity and availability at the time. Meanwhile, transportation cost and equipment operating cost at the terminal will be dramatically increased compared to the former problem. Correspondingly, the port throughput will also be increased to compensate.

In this study, a new systematic methodology together with a mixed integer nonlinear programming (MINLP) model for simultaneous planning of berth and yard allocation for container vessels have been developed. We consider the simultaneous planning problem at the tactical level. This implies that certain decisions have already been made at a strategic level. The objective of this problem is to simultaneously optimizes spatial schedules for both vessels and containers to minimize the total handling time of all vessels, which is equivalent to maximizing the port throughput, subject to various port resource limits and operating constraints. It incorporats proactive robustness into the nominal berth and yard planning by introducing predetermined flexible vessel arrival and departure time windows. The well-known McCormick relaxation is employed to transform the MINLP model into a MILP model. CPLEX has been employed to obtain the optimal solutions of the developed MILP model. And detailed case study will be followed to demonstrate the efficacy of the developed methodology and simultaneous planning model.