๐ฆ๐ฝ๐ผ๐๐๐ถ๐ป๐ด ๐ง๐ฟ๐ผ๐๐ฏ๐น๐ฒ ๐๐ฎ๐๐ ๐๐ถ๐๐ต ๐๐ผ๐ป๐๐ฟ๐ผ๐น ๐๐ต๐ฎ๐ฟ๐๐
One of the fastest ways to stop firefighting and start improving is to see when your process is sending a real signal. That is exactly what SPC control charts do, and Nelsonโs 8 Rules are the cheat codes for reading those signals quickly.
๐๐ฒ๐ฟ๐ฒ ๐ถ๐ ๐๐ต๐ฒ ๐ถ๐ฑ๐ฒ๐ฎ ๐ถ๐ป ๐ฝ๐น๐ฎ๐ถ๐ป ๐น๐ฎ๐ป๐ด๐๐ฎ๐ด๐ฒ:
โ
A control chart displays your process over time, featuring a center line and control limits.
โ
When the dots behave randomly, variation is normal.
โ
When the dots form certain patterns, the process is likely being pushed by a special cause that you can fix.
๐ง๐ต๐ฒ ๐ด ๐๐ถ๐ด๐ป๐ฎ๐น๐ ๐๐ผ ๐๐ฎ๐๐ฐ๐ต ๐ณ๐ผ๐ฟ
๐ญ. ๐ข๐ป๐ฒ ๐ฝ๐ผ๐ถ๐ป๐ ๐ฏ๐ฒ๐๐ผ๐ป๐ฑ ๐๐ต๐ฒ ๐น๐ถ๐บ๐ถ๐
Big outlier. Something unusual just happened.
๐ฎ. ๐ก๐ถ๐ป๐ฒ ๐ฝ๐ผ๐ถ๐ป๐๐ ๐ผ๐ป ๐ผ๐ป๐ฒ ๐๐ถ๐ฑ๐ฒ ๐ผ๐ณ ๐๐ต๐ฒ ๐บ๐ฒ๐ฎ๐ป
Sustained shift. The process likely moved up or down.
๐ฏ. ๐ฆ๐ถ๐
๐ฝ๐ผ๐ถ๐ป๐๐ ๐ฟ๐ถ๐๐ถ๐ป๐ด ๐ผ๐ฟ ๐ณ๐ฎ๐น๐น๐ถ๐ป๐ด
Trend. Think wear, drift, or a setting that is slowly changing.
๐ฐ. ๐๐ผ๐๐ฟ๐๐ฒ๐ฒ๐ป ๐ฝ๐ผ๐ถ๐ป๐๐ ๐๐ฝโ๐ฑ๐ผ๐๐ปโ๐๐ฝโ๐ฑ๐ผ๐๐ป
Overcontrol. Too many adjustments, not enough patience.
๐ฑ. ๐ง๐๐ผ ๐ผ๐ณ ๐๐ต๐ฟ๐ฒ๐ฒ ๐ป๐ฒ๐ฎ๐ฟ ๐๐ต๐ฒ ๐น๐ถ๐บ๐ถ๐ ๐ผ๐ป ๐๐ต๐ฒ ๐๐ฎ๐บ๐ฒ ๐๐ถ๐ฑ๐ฒ
Large shift forming. Investigate now.
๐ฒ. ๐๐ผ๐๐ฟ ๐ผ๐ณ ๐ณ๐ถ๐๐ฒ ๐บ๐ผ๐ฑ๐ฒ๐ฟ๐ฎ๐๐ฒ๐น๐ ๐ณ๐ฎ๐ฟ ๐ณ๐ฟ๐ผ๐บ ๐๐ต๐ฒ ๐บ๐ฒ๐ฎ๐ป
Smaller shift forming. Catch it early.
๐ณ. ๐๐ถ๐ณ๐๐ฒ๐ฒ๐ป ๐ฝ๐ผ๐ถ๐ป๐๐ ๐ฝ๐ฎ๐ฐ๐ธ๐ฒ๐ฑ ๐ป๐ฒ๐ฎ๐ฟ ๐๐ต๐ฒ ๐บ๐ฒ๐ฎ๐ป
Stratification or measurement issue. You may be mixing data, or the gauge is masking real movement.
๐ด. ๐๐ถ๐ด๐ต๐ ๐ฝ๐ผ๐ถ๐ป๐๐ ๐ณ๐ฎ๐ฟ ๐ณ๐ฟ๐ผ๐บ ๐๐ต๐ฒ ๐บ๐ฒ๐ฎ๐ป ๐ผ๐ป ๐ฏ๐ผ๐๐ต ๐๐ถ๐ฑ๐ฒ๐
A mixture of different sources. Separate streams and check settings.
๐ช๐ต๐ ๐๐ต๐ถ๐ ๐บ๐ฎ๐๐๐ฒ๐ฟ๐ ๐๐ผ ๐๐ผ๐
โก๏ธYou stop guessing. You know when to act and when to leave the process alone.
โก๏ธYou reduce rework and overtime by catching issues days or weeks earlier.
โก๏ธYou earn trust. Leaders love seeing problems flagged with evidence, not opinions.
๐ค๐๐ถ๐ฐ๐ธ ๐๐๐ฎ๐ฟ๐
โก๏ธPick one important metric.
โก๏ธCollect 20 to 25 points in time order.
โก๏ธBuild a simple control chart and scan for the 8 rules.
โก๏ธWhen a rule triggers, ask: what changed in materials, methods, machines, people, or environment?
If you want to apply this to a real project and learn the rest of the Six Sigma Circuit ยฎ๏ธ tools, join our next class:
๐๐ข๐ฑ ๐๐ข๐ ๐ฆ๐ ๐๐
Real Projects. Real Results. No Paper Belts.
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Six Sigma Green Belt for Services: www.6sigmaph.com/greenbelt
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