The PDCA cycle (Plan-Do-Check-Act) is a four-step, iterative method for solving problems and improving processes: you plan a change, test it on a small scale, check the results against a target, then act by standardizing what worked or refining what didn’t. Because the four steps close into a loop, every pass feeds learning into the […]
Western Electric Rules (1-8) in Control Charts Signals
The Western Electric Rules are a set of eight statistical decision rules used to detect special cause variation on a control chart. First published in the Western Electric Company’s Statistical Quality Control Handbook in 1956, they flag non-random patterns — shifts, drifts, and trends — before a point ever crosses a control limit. The rules […]
Gage R&R – MSA (Measurement System Analysis) Study Explained
A Gage R&R study (Gage Repeatability and Reproducibility) is a structured experiment that determines how much of your observed variation comes from the measurement system rather than from the parts themselves. In the standard crossed design, 3 operators measure 10 parts 3 times each, and the 90 results are decomposed into repeatability (equipment variation), reproducibility […]