FUTUREMATH Ltd
Agent-Based Models are a relatively recent advance in the science of mathematical modeling. They are different from more traditional methods such as system dynamics and discrete-event simulation in that they model a system in a non-deterministic way (i.e. with the quirks and unpredictability inherent in the way real people behave).
In these models, agents are the individual elements of a system (they could be people, vehicles, etc), and are often only represented in terms of their most relevant details. The multiple interaction of the agents often generates what is called “emergent behavior”, that is, the behaviour of the system as a whole is often not understandable by examining its parts in isolation.