A process fills soda into cans. 3-sigma control limits for the mean are calculated to monitor the ounces of soda filled into cans.

This means that there is:

• Less than a 1% chance that a can will have less soda than the lower control limit
• A 1% chance that the process will be out of control
• Less than a 1% chance that a can will have more soda than the upper control limit
• Less than a 1% chance that a sample mean will fall outside the control limits