When learning about Six Sigma, it may help to consider these charts, which detail how sigma level relates to defects per million opportunities (DPMO), and some real-world examples.
Sigma Performance Table
|Sigma Performance Levels – One to Six Sigma|
|Sigma Level||Defects (or Errors) Per Million Opportunities (DPMO)||Yield (or Produced or Delivered) Correctly (%)|
What Would Sigma Values Look Like In The Real World?
It’s one thing to see the numbers and it’s a whole other thing to see how it would apply to your daily life.
|Real-world Performance Levels|
|Situation or Example||In 1 Sigma World||In 3 Sigma World||In 6 Sigma World|
|Pieces of your mail lost per year [assuming 1,600 opportunities per year]||1,106||107||Less than 1|
|Number of aircraft takeoff or landing incidents [assuming one takeoff and landing per flight, round trip]||25 times per 10 flights||24 times per 100 flights||12 times per million flights|
|Number of empty coffee pots at work (who didn’t fill the coffee pot again?) [assuming 680 opportunities per year]||470||45||Less than 1|
|Number of telephone disconnections [assuming 7,000 talk minutes]||4,839||467||0.02|
|Erroneous business orders [assuming 250,000 opportunities per year]||172,924||16,694||0.9|
|Electricity outage [assuming 30 day month = 720 hours]||500 hours||45 hours||9 minutes|
In the United States alone if the sigma level were between 3 and 4, there would be 50 newborn babies dropped per day and 5,000 incorrect surgical procedures per week.
Not all opportunities and defects are created equal. I think all flight passengers would agree that a flight delay is less worrisome than a flight incident on landing.