Open-loop control is a process that systematically targets variables in a controllable system which is referred to as a controlled system or controlled object and is typically a device, machine, machine system, or technical plant in which substances or energy are acquired, transferred, converted, stored, or used as intended.
Open-loop control is an effective way of influencing the operation of a device or process in line with a defined plan. Output variables (motor, valve) are set a function of the input variables (switch, time) and status variables (motor running, current temperature).
Unlike closed-loop control, open-loop control does not include continuous feedback of the output variable to the input because the result is not checked. It is, therefore, an open loop of action. See Fig. 1 Closed-loop control