Is 99.9% an acceptable tolerance for defects?

Consider:

• Drinking water contaminated for 1 hour per month.
• 16,000 letters lost every day by the US Post Office.
• 2 accidents per month at O’Hare International Airport.
• 20,000 prescriptions in error each year.
• 50 babies dropped on the delivery room floor each hour.
• 22,000 checks drawn from the wrong account per hour.

From the Script: SLIDE 9 - Do Defects Really Matter?

What do these differences in defect rates really mean? Is there any significance to them?

To demonstrate the real impact of defects, let's consider the following:

Would you consider it acceptable for the following processes to be 99.9% reliable? Each 0.1% defect rate would result in an additional:

• 1 hour per month of contaminated drinking water.
• 16,000 letters lost every day by the US Postal Service.
• 2 accidents per month at O'Hare International Airport.
• 20,000 erroneous drug prescriptions each year.
• 50 babies dropped on the delivery room floor each hour.
• 22,000 checks drawn from the wrong account per hour.

From these examples, I think we can see that it is in our best interest to limit our exposure to any more risk than is necessary... especially if its your business, your money, or, in the case of DOD, your life at risk.