multi-agent systems for container terminal management

Introductiongoals. To meet these goals, an agent is able to execute plans overtime.• Mobility: An agent is able to change its location within a physicalor virtual environment (e.g. a computer simulation model)• Reactivity: An agent is able to respond to changes in its environmentin a timely fashion.• Situatedness: An agent inhabits or occupies some environment thatit can sense and act upon.• Sociality: In order to reach its goals an agent communicates andinteracts with other agents in a cooperative or competitive mannerThe use of agents has evolved from concepts found in object orientedprogramming. In object oriented programming, objects maintaintheir parts of code (or methods) and local control over the variablesmanipulated by its methods. The difference between objects and softwareagents is that objects are considered to be passive since theirmethods are invoked by external entities, whereas software agentsmaintain their own thread of control, localising not only code and statebut their invocations [20]. Parunak suggests that agents are appropriatefor applications that are characterised as modular, decentralised,changeable, ill-structured, and complex [21]. The qualities listed by Parunakfor using agent technology can be identified in the CT managementdomain.• Modular: Each decision maker in a CT and the resources used forexecuting tasks can be seen to have its own set of state variablesthat are distinct from the environment.• Decentralized: A set of actors in a CT can be decomposed intostand-alone processes, each capable of doing useful things withoutcontinuous direction by the other actors/processes. This alsominimizes the impact that changing one module has on the behaviourof other modules.• Changeable: The structure of a CT is afflicted with change as thatcontinuously new ships are entering while others are leaving, witheach ship having its own unique demands and configurations.• Ill-structured: Complete information on all the processes for managingthe CT is not achievable due to the current prevailing state of11