An engine manufacturer uses a forging process to make piston rings. The quality engineers want to assess the process capability. They collect 25 subgroups of five piston rings and measure the diameters. The specification limits for piston ring diameter are 74.0 mm ± 0.05 mm.
You can use this data to demonstrate Normal Capability Analysis or other analyses that use normally distributed data.
|Diameter||The diameter of each piston ring. Every 5 rows represent a subgroup.|
Data are from Douglas C. Montgomery (2005). Introduction to Statistical Quality Control. John Wiley & Sons, New York.