LPWS Basic Knowledge Practice Exam 2026 - Free LPWS Practice Questions and Study Guide

A control chart is about watching how a process behaves over time and spotting when changes are just normal wiggle versus when something unusual is happening. By plotting a quality measure over time and drawing a center line (the average) along with upper and lower control limits, you can judge whether the process stays in statistical control. When most points stay within the limits and patterns look random, the process is stable. If a point falls outside the limits or you see non-random patterns like trends or runs, that signals a special cause that should be investigated. This helps keep quality consistent and lets you react quickly to issues before they create defects. Documents of steps, forecasting demand, or certifying people serve different purposes, so they aren’t the focus of a control chart.