In-Control process

(1) A process in which the statistical measure being evaluated is in a state of statistical control; in other words, the variations among the observed sampling results can be attributed to a constant system of chance causes. Also see "out-of-control process."

(2) A process is said to be "in control" or "stable" if it is in statistical control. If a process is in statistical control, a control chart will have no subgroups falling outside the control limits, no runs, and no nonrandom patterns.