This document provides an overview of statistical process control (SPC). It discusses using control charts like X-bar, S, and R charts to monitor variables like a pipe's height, diameter, and weight in a pipe manufacturing process. It also mentions using an exponentially weighted moving average (EWMA) to identify small process shifts. The goal is to determine whether the process is in or out of control and identify any assignable causes if it is out of control, so corrective steps can be taken.