A Discrete Event Simulation Model For The Analysis Of Critical Factors In The Expansion Plan Of A Marine Container Terminal

Abstract

In this paper we present a discrete event simulation model to approach the decision problems arising from an expansion plan of a marine container terminal. In particular the preliminary study herein presented starts from a collaboration with the Southern European Container Hub (SECH) sited in the Port of Genoa, Italy. The planned expansion will take place from 2010, the terminal area will enlarge, thus being capable of doubling the present TEU handling capacity. Due to the foreseen increase in the traffic volume, there is the need of defining new management policies, mainly related to the organization of the yard and quay sides of the terminal. The proposed simulation model, that has been implemented by the Witness software environment, can be used to analyse different scenarios, pertaining to possible changes of the import/export flows, handling techniques, different equipments and investment options as well as different operative rules for the berthing and storage area. INTRODUCTION AND PROBLEM DEFINITION The steady increasing number of container shipments is causing higher demands at the seaport container terminals, and, consequently, the competition among seaports is increasing too, especially among geographically close ones. The competitiveness of a marine container terminal is based on different factors, such as ship turnaround time, number of TEUs moved per unit of time, combined with low rates for loading and discharging and fast turnover of containers. In general terms, an import/export container terminal can be described as an open system with two external interfaces: the quayside, or marine side interface, with loading and unloading of ships, and the land side interface where containers are moved from/to trucks and trains. A container vessel, after its arrival at the terminal, is assigned to a berth equipped with quay cranes for loading/unloading operations. The import flow starts with unloading operations from the ship; the unloaded containers are transferred by internal transportation equipment, i.e. vehicles, multi-trailers, fork lifts (FL), straddle carriers (SC) or Reach stackers (RS), to the storage area (yard) for their later departure via trucks or trains. In the yard they are stored in stacks using rail mounted gantry cranes (RMG) or rubbed-tired gantry cranes (RTG). Different storage strategies can be used by the terminal yard management i.e. the premarshalling strategy and the sort and store strategy (see e.g. Ambrosino and Sciomachen (2003)). The export flow concerns containers that reach the terminal via trains or trucks, are stored in the yard by using dedicated equipment (see e.g. Vis and Harika (2004) for an overview of vehicle types at a container terminal) and finally are loaded on board for their departure by ship. In general, a marine terminal must be managed in such a way to optimise the collective flows of containers that arrive and leave it via trucks, trains and vessels. An expansion plan can affect the efficiency and the “optimal” management of the whole terminal, thus requiring to analyse the emerging critical factors in the terminal system. In the following we will deal with the issues arising from an expansion plan of a import/export container terminal sited in the Port of Genoa, Italy that is the Southern European Container Hub, SECH. Following the planned expansion, that will take place from 2010, the terminal area will enlarge from 207.000 to 480.000 sqm, thus making the terminal able of doubling the present TEUs handling capacity. Proceedings 23rd European Conference on Modelling and Simulation ©ECMS Javier Otamendi, Andrzej Bargiela, Jose Luis Montes, Luis Miguel Doncel Pedrera (Editors) ISBN: 978-0-9553018-8-9 / ISBN: 978-0-9553018-9-6 (CD) In Figure 1 is depicted the planned change of the terminal layout. Interested readers can refer to the web site http://www.sech.it for getting more information about the terminal SECH and its expansion plan. Terminal design problems, related to the multi-modal interfaces and the equipment type selection, have been approached by facility planners in the first stage of the terminal expansion (see the input data analysis section). The organization of the yard and the quay operations should be revised to be able to meet the new foreseen increased traffic of containers. Terminal managers need to test and compare different new management policies. Their goal is both improving the terminal productivity by a better synchronization among the handling facilities and achieving cost savings related to a better usage of handling and human resources. For this purpose, using the Witness software environment, we have developed a discrete event simulation model. This model can be used for different “what-if” analysis pertaining to possible changes of the import/export flows, handling techniques and equipment, as well as different operative rules for the quay side and yard area.