Exact method for single vessel and multiple quay cranes to solve scheduling problem at port of Tripoli-Lebanon (original) (raw)
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Solving methods for the quay crane scheduling problem at port of Tripoli-Lebanon
RAIRO Oper. Res., 2021
The quay crane scheduling problem (QCSP) is a global problem and all ports around the world seek to solve it, to get an acceptable time of unloading containers from the vessels or loading containers to the vessels and therefore reducing the docking time in the terminal. This paper proposes three solutions for the QCSP in port of Tripoli-Lebanon, two exact methods which are the mixed integer linear programming and the dynamic programming algorithm, to obtain the optimal solution and one heuristic method which is the genetic algorithm, to obtain near optimal solution within an acceptable CPU time. The main objective of these methods is to minimize the unloading or the loading time of the containers and therefore reduce the waiting time of the vessels in the terminals. We tested and validated our methods for small and large random instances. Finally, we compared the results obtained with these methods for some real instances in the port of Tripoli-Lebanon.
2019 IEEE International Conference on Systems, Man and Cybernetics (SMC)
This paper addresses the scheduling problem in port of Tripoli-Lebanon for a single quay crane with multiple yard trucks, all containers that will be unloaded from the vessel are in the same bay. The objective is to reduce the completion time of all containers from the vessel to their store location, we used a mixed integer linear programming and a dynamic programming algorithm to solve the problem. Finally, we have compared and validated our results on real instances from the port.
Computers & Industrial Engineering, 2009
This paper presents a novel, mixed-integer programming (MIP) model for the quay crane (QC) scheduling and assignment problem, namely QCSAP, in a container port (terminal). Obtaining an optimal solution for this type of complex, large-sized problem in reasonable computational time by using traditional approaches and optimization tools is extremely difficult. This paper, thus, proposes a genetic algorithm (GA) to solve the above-mentioned QCSAP for the real-world situations. Further, the efficiency of the proposed GA is compared against the LINGO software package in terms of computational times for smallsized problems. Our computational results suggest that the proposed GA is able to solve the QCSAP, especially for large sizes.
Mathematical model for Quay Crane Scheduling Problem with spatial constraints
In the last decades, competition between port container terminals, especially between geographically close one, is rapidly increasing. To improve this competitiveness, terminal managers try to achieve rapid container vessel loading and unloading, that corresponds to a reduction of the time in port for vessels. In this paper, we focus our attention on the operational decision problem related to the seaside area of maritime container terminals. In particular, we study The Quay Crane Scheduling Problem (QCSP) which is considered as a core task of managing maritime container terminals and the optimization of these operations affects significantly the time spent by vessels at berth. The main goal behind this planning problem is to find the optimized sequence of loading and unloading tasks on a set of deployed quay cranes in order to exploit the full performances of port's resources while reducing the berth's total time occupation by vessels. In this paper, we provide a rich model for quay crane scheduling problem that covers important parameters such as ready time and due dates of Quay cranes (QCs), safety margin in order to avoid congestion between QCs and precedence relations among tasks. The proposed model seeks for a more compact mathematical formulation that can be easily solved by a standard optimization solver. Thus, we formulated the Quay Crane Scheduling Problem as a mixed-integer linear model that minimizes the sum of the QCs holding cost and tardiness penalty cost.
Operations Research Proceedings, 2013
In this work, we focus on the integrated planning of the following problems faced within the context of seaside operations at container terminals: berth allocation, quay crane assignment, and quay crane scheduling. First, we formulate a new binary integer linear program for the integrated solution of the berth allocation and quay crane assignment problems called BACAP. Then we extend it by incorporating the crane scheduling problem as well, which is named BACASP. Although the model for BACAP is very efficient and even large instances up to 60 vessels can be solved to optimality, only small instances for BACASP can be solved optimally. To be able to solve large instances, we present a necessary and sufficient condition for generating an optimal solution of BACASP from an optimal solution of BA-CAP using a postprocessing algorithm. We also develop a cutting plane algorithm for the case where this condition is not satisfied. This algorithm solves BACAP repeatedly by adding cuts generated from the optimal solutions at each trial until the aforementioned condition holds.
Naval Research Logistics (NRL), 2006
In this paper, we study the problem of scheduling quay cranes (QCs) at container terminals where incoming vessels have different ready times. The objective is to minimize the maximum relative tardiness of vessel departures. The problem can be formulated as a mixed integer linear programming (MILP) model of large size that is difficult to solve directly. We propose a heuristic decomposition approach to breakdown the problem into two smaller, linked models, the vessel-level and the berth-level models. With the same berth-level model, two heuristic methods are developed using different vessel-level models. Computational experiments show that the proposed approach is effective and efficient.
European Journal of Operational Research, 2016
There has been a dramatic increase in world's container traffic during the last thirty years. As a consequence, the efficient management of container terminals has become a crucial issue. In this work we concentrate on the integrated seaside operations, namely the integration of berth allocation, quay crane assignment and quay crane scheduling problems. First, we formulate a mixed-integer linear program whose exact solution gives optimal berthing positions and berthing times of the vessels, along with their crane schedules during their stay at the quay. Then, we propose an efficient cutting plane algorithm based on a decomposition scheme. Our approach deals with berthing positions of the vessels and their assigned number of cranes in each time period in a master problem, and seeks the corresponding optimal crane schedule by solving a subproblem. We prove that the crane scheduling subproblem is NP-complete under general cost settings, but can be solved in polynomial time for certain special cases. Our computational study shows that our new formulation and proposed solution method yield optimal solutions for realistic-sized instances.
Transactions on Computational Science and Computational Intelligence
This paper discusses the jointly quay crane and yard truck scheduling problems (QCYTSP) with unloading and loading containers from/to vessel(s) in the same time. Yard trucks transport the containers to/from yard locations with all containers that are homogeneous. We propose a mixed integer linear programming model to solve the scheduling problem. We consider in this study, the quay crane interference, containers precedence and safety margin. The main objective is to minimize the total completion time of the vessels.
Assignment and deployment of quay cranes at a maritime container terminal
2008
The complex logistic process of vessel berthing followed by container discharge/loading, at maritime container terminals (MCTs), is focused in this paper. Discrete-event simulation models are well capable of representing the entire process in a stochastic, dynamic environment. Hence, simulation results to be an effective planning and control tool for decision making and evaluation. The assignment of quay cranes to berthed vessels and their deployment along the berth represent crucial decisions that could be well supported by integer programming (IP) models. Usually, these models are used as standalone tools. Starting from a discrete-event simulator for the berth planning, previously developed for a real maritime container terminal, we propose two IP models that can be embodied within the simulator to verify whether or not the weekly plan of the berth schedule produced by the simulator itself is feasible with respect to the available quay cranes. If not, the manager would be asked to repeat the berth planning step by rerunning simulation. The goodness of the proposed IP formulations is established by a numerical comparison against a test case taken from literature.
Optimization Process for Berth and Quay-Crane Assignment in Container Terminals with Separate Piers
Athens Journal of Τechnology & Engineering
The objective of this research is the study of container terminals with two separated piers within the same port basin. The main problem is how to optimize the berth and crane allocation and to minimize the overall service time for the vessels and to improve the utilization of the terminal assets. The optimization of the seaside subsystem of the container terminals combines three typical operational problems: ship-to-berth allocation, quay-crane to ship assignment and quay-crane scheduling. Due to their characteristics, they have a high correlation and should be considered together. The problem can become even more complex in the Container terminals with a different layout where quays and berths are not placed in the line or where berths are situated in different piers. In this paper, a specific methodology is presented with a focus on the optimization process. This process consists of three stages namely: initiation, allocation and adjustment. The core of the problem solutions in stage 1 is the execution of crane scheduling problem according to cargo volume and container distribution on the vessel. The result of this stage is three operational scenarios that set out two key variables: duration of the handling process and the number of cranes required. According to the results from stage 1, ship-to-berth assignment and allocation of cranes isexecuted. The practical approach implemented here, targets to high prediction, reliability and efficiency of the operational plans to satisfy the requirements of the shipping companies. This approach requires a fixed number of quay-cranes during the handling operations and high utilization rate of the cranes. The results of the overall optimization have been shown on the few examples.