Computer-implemented simulations need not per se interact with physical reality in any way, apart from the electrical currents generated in the computer’s circuitry. Simulations may be used to investigate the behaviour of physical systems or processes in the absence of an actual physical instantiation of the system or process in question. Since producing such a physical embodiment may be costly in terms of physical resources, time and so on, a simulation may be an efficient alternative.
Furthermore, simulations may allow the investigation of properties of systems or processes on massive scales, in ways that are not practically feasible to perform in physical reality. For instance, the statistical behaviour of a system or process can be evaluated using a large set of different initial and boundary conditions. Simulations also have great value in investigating, in particular optimizing, the behaviour of a technical/physical system as well as the interaction between humans and the system in question under conditions that can hardly or not at all be investigated in an actual physical installation, since it would result in the destruction of the system and/or even be dangerous. Examples are the operation of a system beyond the specified design limits or in hazardous situations, such as in the event of an accident, fire or the like.