By one sided I mean the specification is X <= 32 and surface finish cannot physically go below 0.
There is no target, you have the whole 0-32 range to play with.
I suppose you could make it an attribute by just saying it has to be <=32.
But we have customers who want the data analyzed.
On a 30 piece sample it's a pretty wide, (and pretty normal) distribution so I'm getting one sided Cpk vaues in the range of .65.
But all pieces are in spec with a range of 8 - 29.
When I calculate z it comes out to better than 3.0.
How do I defend this to a customer who is hung up on Cpk?
The only way to get better is to slow down the cutting process, which will add cost.
There is no target, you have the whole 0-32 range to play with.
I suppose you could make it an attribute by just saying it has to be <=32.
But we have customers who want the data analyzed.
On a 30 piece sample it's a pretty wide, (and pretty normal) distribution so I'm getting one sided Cpk vaues in the range of .65.
But all pieces are in spec with a range of 8 - 29.
When I calculate z it comes out to better than 3.0.
How do I defend this to a customer who is hung up on Cpk?
The only way to get better is to slow down the cutting process, which will add cost.