A Sigma Score is calculated as DPMO, Defects Per Million Oportunities, a Six Sigma process with a Sigma Score of 6 will achieve 3.4 DPMO or 99.99966%.


99% effective or 3.8 sigma

20,000 pieces of post lost each hour of each and every day.
Drinking water unsafe to drink for about 15 minutes each day.
5,000 mistaken hospital surgical operations every week.
2 long or short aeroplane landings daily at major airports.
200,000 incorrectly prescribed drug prescriptions every year.
No electricity and blackouts for nearly 7 hours every month.
11.8 million stocks wrongly traded on the New York Stock Exchnge each day.
3 warranty claims on all new automobiles.
48 - 96,000 deaths linked to hospital blunders every year.

99.99966% effective or 6 sigma

Only 7 pieces of post lost each hour of each and every day.
60 seconds of unsafe drinking water every 7 months.
1.7 wrong hospital surgical operations each and every week.
1 long or short runway landing at a major airport every 5 years.
68 mistakenly prescribed drug prescriptions every year.
Only 1 hour without electric power every 34 years - fantastic.
4,021 shares wrongly traded on the New York Stock Exchange each day.
Only 1 warranty claim on every 980 new cars.
17 to 34 deaths caused by hospital blunders each year.