Research On Equipment Configuration Optimization Of Container Terminal Based On Queueing Network Theory

With the rapid expansion of containerized cargo transportation as a result of the globalization of economy and trade in the world, the container port terminals in China are faced with more challenges as well as opportunities.To provide better instruction on operation practice on container terminals in our country and improving the efficiency of the port operation, the dissertation has studied the operation system of container terminal based on queueing theory through simulation. The configuration of important equipments is explored in this thesis including the quay cranes, the handling equipment in container yard, and the container vehicles that are very important to the operation efficiency in the port.It is discussed in this thesis the characteristics of the equipment resource in container terminal including the berth, the yard, the quay cranes, the handling machine, the transporting machine, the human resource, the information resource and the energy and so on. The proper configuration of equipments has played an important role in the optimization of container terminal operations. Through a spot investigation in Nibo container terminal and the statistics of real data, the data is analyzed to obtain the distribution of the ship length, the quantity of containers to be handled, the average efficiency of single quay crane, the workload of quay cranes, and yard cranes and the vehicles. From the statistical results, it is concluded that the quay cranes has been configured with too much arbitrary and the workload of handling and transporting equipments is unbalancedly distributed.In Chapter 4, firstly, the queueing theory is introduced into the research of the quay crane service system at front berths. The container truck is assumed as client and the quay cranes as server in the queueing system. Based on the queueing theory and the simulation method, the real probability distributions of the interval time of trucks as arriving at the berth, and the service time of the quay cranes are concluded through statistical calculation. On this basis, an M/M/m queueing model is developed to describe the quay crane service system. Through simulation, how the performance indicators vary with the quay cranes increasing is investigated. In the simulation results, an inflexion point is always founded in almost every one of the curves of the indicators versus the quantity of quay cranes. The value of x coordinate of the inflexion is just the optimal quantity of cranes in a test. Through regression, a good correlation is founded between the optimal number and another two parameters. As a result, some suggestions are conducted. Increasing the quantity of quay cranes does not necessarily result in the improvement of the service ability of the system. It should be decided in accordance with the ratio of the quay crane service efficiency and the arriving frequency of trucks. After the quantity is decided, some measures could be taken to properly configure the trucks to realize the high service efficiency and reduce the queueing length and the traffic jam at front berth.To study the operation of container terminal in a more overall way, a parallel queueing model is developed in Chapter 5 to describe the service system when multi ships are berthed to study the balanced configuration of quay cranes among multi ships under limited crane resource. After that, the M/G/1 queueing model is explored to fit the normal-distributed service time with much more adaptability.As for the cyclic operation between the quay cranes and the RTGs, a two-stage cyclic queueing model is developed with the assumption of the trucks as client, the quay crane and the RTG as servers. The system performance is studied on the rule how it approaches to an equilibrium state. Some advice is given on the joint configuration of quay cranes and RTGs.On the basis of a real large container port terminal, an operation simulation system has been developed on the Witness 2004 platform through efforts, in which a transportation road network from the front berth to the container yard is included. It provides convenient adaptive parameters and friendly interface to operators and researchers. Based on this simulation system, the container trucks configuration is studied as a case study. Through running the model, the effect of the quantity and the speed of the container trucks are analyzed on the ship handling time. It is concluded that for the sake of efficient operation, the quantity of the trucks should be configured dynamically according to the different period of handling, and that a higher speed of the trucks would not necessarily result in a faster handling efficiency.At the end of the dissertation, it points out that some researches could be conducted further in future. The simulation system of container terminal in this paper has provided basic techniques and experience to further develop an embedded tool of the Operation Decision Support System. As a plug-in optimization module combined with the management Information System (MIS), it could utilize the mass data in production database of the container terminal to support decision, improve the operation decision level, improve the production efficiency and decrease the operation cost.