process simulation.
The basic model components are
Each collect and report statistical data about their use.
In a process-oriented model, queues are used to synchronise simulation processes which are conceptually acting concurrently. For example, in a loading zone of a container terminal, arriving trucks had to wait until a van carrier was available for service.
Patterns of synchronisation between process:
A single simulation run will not offer reliable results, since they are the outcome of a stochastical process.
Discrete event simulation describes a process with a set of unique, specific events in time. They can simulate almost any process.
All system state changes are supposed to happen at discrete points in time. Between such events the system state is assumed to remain constant. Discrete-event simulation is therefore particularly suitable for systems in which relevant changes of state occur suddenly and irregularly, like queueing networks for example.
wiki/Discrete_event_simulation