Page 63 - Six Sigma Yellow Belt

5 Whys

Here's an example of how the 5 Whys could be used in Six Sigma:

Problem: A manufacturing company has experienced an increase in customer complaints about product

defects.

1.Why are customers complaining about product defects? Because the products are not meeting their

expectations.

2.Why are the products not meeting their expectations? Because the products are not meeting the
required specifications.

3.Why are the products not meeting the required specifications? Because the manufacturing process is

not consistent.

4.Why is the manufacturing process not consistent? Because the machinery is not calibrated properly.
5.Why is the machinery not calibrated properly? Because the maintenance schedule is not being

followed consistently.