Evaluating Container Terminal Transhipment Operational Policies: An Agent-Based Simulation Approach LAWRENCE HENESEY, PAUL DAVIDSSON, JAN PERSSON Department of Systems and Software Engineering Blekinge Institute of Technology Biblioteksgatan 4, Karlshamn, 374 24 SWEDEN {lhe, pdv, jps}@bth.se http://www.bth.se/ Abstract: - The problem of analysing operational policies for transhipping containers in a port container terminal is studied using an agent-based simulation approach. The decision makers involved in transhipment operations, i.e., the terminal manager, the port captain, the stevedores and the ship captains, as well as some of the operators of the physical resources, such as cranes and straddle carriers, are modelled as agents. A simulator, called SimPort, has been developed to illustrate the viability of this approach, To exemplify its usage, it has been configured based on real data from container terminals and used for comparing eight operational policies in several scenarios. The policies concern the sequencing of ships, berth allocation, and stacking rule. The policies are evaluated with respect to a number of aspects, such as, turn-around time for ships and travelled distance of straddle carriers. Key-Words: - Container Terminal, Agent-Based Simulation, Transhipment Operations, Berth Allocation, 1 Introduction The number of Twenty-foot Equivalent Unit containers (TEUs) shipped world-wide has increased from 39 million in 1980 to 356 million in 2004 and growth is still projected at an annual growth rate of 10% till 2020 [1]. Ports and container terminals (CTs) are trying to meet increasing demand by creating additional capacity. According to Drewry consultants, the cost for planning for container terminals in Northern Europe for 2004 is €549 million with total project costs reaching €6081 million [1, 2]. Many of the solutions considered can be classified as either physical expansion or increasing terminal performance. Some types of physical expansion solutions are purchase of new or additional equipment, hiring more labour, development and purchase of IT systems. Solutions that can be classified as increasing terminal performance may include the use of optimisation and simulation technologies to use the available resources more efficiently. There has been much research on improving CT effectiveness, e.g., [3, 4, 5]. Henesey [6] concludes that simulation models have been used extensively in understanding the behaviour, experimenting and testing conditions and scenarios due to the cost and complexity of the CT domain. A number of simulators and simulation models have been developed in studying CTs and they differ widely in objectives, complexity and details, but all suggest or propose a centralized system for scheduling or controlling [7]. Although a distributed approach has been investigated by a number of researchers using agent technology, such as [8-15], most of the work has focused on techniques for automating or controlling the operations in a CT. This paper presents a multi-agent based simulation (MABS) approach to evaluating different operational policies for increasing terminal performance. A simulator, called SimPort, has been developed to show the viability of this approach. The agent based approach offers the power of modelling the decision making processes of different actors. An application that may benefit in using an agent based approach is the operations of transhipping containers in a CT. The remainder of the paper is organized in the following way; first a general description of the CT transhipment processes is provided, then the agent- based simulator is presented. The design of the experiments is explained in section 4 which is followed by a description of the results that are analyzed and discussed. Finally, some conclusions are presented together with pointers to future work. 2 Container Terminal Description Container handling activities in CT are shown to be dependent on various related subsystems [16]. The managers involved are generally referred to as