A Simulation system mimics certain characteristics of one or more physical objects, even when the objects exist only as a concept or specification. In industry, computer systems are used to simulate a diverse range of characteristics and objects, for example (1) strength of a mechanical component (2) airflow to cool an electronic circuit (3) throughput of a set of production machines (4) behaviour of a mechanism in motion. Engineers use simulation to help design and improve products and systems without having to build and test prototypes. Operators use simulation for training, for example, to learn how to operate machinery.