Evaluation of operational plans in container terminal yards using Discrete-Event Simulation

As the world container volumes are soaring, container terminals form a very important chain in the global transportation network. It is a generally accepted view that the modelling of the dynamic and stochastic nature of the container terminal systems using analytical or closed form models is a complicated process and the use of such models is very limited. Hence, this paper presents a simulation model for complete terminal operations which is developed and implemented with the view to validate/ evaluate the operational results obtained from a new optimization model of the combined container assignment and yard crane deployment problem. The various aspects of the container terminal operations are modelled using discrete-event simulation. Computational results from the simulation model are reported for a UK container terminal using operational data. Introduction Ninety five percent of the international cargos today go through the major sea ports (Gambardella, Mastrolilli et ai, 2001). Thus, container terminal operations are of great importance to global supply-chains. However, due to their complexity, the use of analytical models is very limited and, hence, simulation has become increasingly popular among researchers to emulate or imitate the terminal operations. A container terminal can be divided into three parts: gate, yard and quay. Containers are categorised as import, export or transhipment. Import containers are discharged from the ship, temporarily stored in the yard and are collected by the agent for local consumption. The reverse flow is true for export containers which come to the terminal via the gate to be loaded onto a loading vessel. Transhipment containers are unloaded from the discharging vessel, assigned to a yard location and loaded onto another vessel so that they are transported to their destination. The graphical representation of container flows in a typical container terminal is shown in Figure 1. For a literature review on container terminal operations, refer to Ma and Hadjiconstantinou (2005), Stahlbock and VoS (2008), Steenken, VoS et ai (2004), Vis and de Koster (2003). Figure 1: Container flows in the yard rtf til T h' rans rprnen mpo ImportlExport Container Export