Statistical Process Control (SPC) is a data driven approach for monitoring and controlling a process or production method. It involves collecting and analyzing data about a process. By using statistical techniques, the analysis can go beyond a simple pass/fail test, and identify drifts in a process before the drift is large enough to produce non-compliant results.
SPC is often implemented using charts for operators to check. In advanced systems, adjustments are made automatically when readings indicate that a control limit is being approached.