Simulation Researched Of Yard Gate System On Container Terminals Based On WITNESS

Along with the development of the global economy integrating, the port has become an important node of the transportation and the supply chain. The yard gate system on container terminals is the operation channel for trucks to carry containers to move into or out of the container yard and is the important role in the operations of container yard. Actually, the performance of the gate system plays an important role in enhancement of service quality of ports.At the beginning, the paper review on the domestic and abroad researches of container terminal system. Then the paper introduces the modeling methods and strategies of discrete event dynamic systems. It also explains the computer simulation technology and approach of simulation optimization used in container terminals system in domestic and overseas.Secondly, the paper discusses the operation flow of the gate system on container terminal. One working year data is analyzed to gain the necessary discrete distributions. The yard gate system is considered the uncertain and stochastic activities in the system; the discrete-event system simulation model based on queue theory is built, and simulates operations of the actual system with simulation software Witness. Moreover, validate the simulation model so that the model can be considered to be accurately representing the real system.Thirdly, The yard gate system is researched by the buliting model. It will analyze the facility efficiency and give the best scheme of the gate numbers considering the container terminal's throughput is not change. And it will analyze the Present most Productivity of the gate system on container terminal considering the scheme of the gate numbers is not change by the simulation model.At last, according to the disproportion of the amount of arriving trucks, gate system's online real-time scheduling operation is discusses. The formulation of mathematical programming model is established to optimize the number of gate lanes in every scheduling interval in one day, including the scheduling objectives and constraints according to the scheduling operations analysis of the gate system. The yard gate system on container terminals will be used effectively by accept the result of simulation optimization.