Forget all this nonsense about Normal distributions and capability indices. how much variation does the process have vs the spec limits? Plot the histogram. Plot the time series / control chart is it stable?
If the hole is at it's minimum specified size, and the thing that goes into it is at it's maximum will fit it correctly or are there stackup concerns?
Now how much variation can you allow? that is your goal.
You should spend MORE TIME working on determining what the product truly requires to meet customer performance needs and determining the critical input factors for your process and how to control them...once youknow hat to do and how to accomplish it consistantly the capability index is irrelevent. the plot of the data vs teh spec limits will tell the story. capability indexes only hide the true nature of your variation...
If the hole is at it's minimum specified size, and the thing that goes into it is at it's maximum will fit it correctly or are there stackup concerns?
Now how much variation can you allow? that is your goal.
You should spend MORE TIME working on determining what the product truly requires to meet customer performance needs and determining the critical input factors for your process and how to control them...once youknow hat to do and how to accomplish it consistantly the capability index is irrelevent. the plot of the data vs teh spec limits will tell the story. capability indexes only hide the true nature of your variation...