M
mlee97
Hi guys! I have a particular problem with a machining capability study in which I am butting heads with a Ford SSBB SQA.
We performed a Surface finish run on a capability run. 300+ pieces sampled to get 125 pieces (25 sets of 5). Ford Requires a PPK of 1.67 on these and control.
When we crunched the data in Minitab, we got a PPK of 17.85 but we had a control point out on the R chart of the required 6-pack.
I complained because the control limits are so tight because of the very limited amount of variation in the machining process. The span of the control limits is less than the unit of measurement (RZ) and the sigma is less than the resolution found in the MSA. He didn't buy it. He said I had to remeasure, but I balk because I know that I am simply in the noise zone of the measuring process.
How do you guys argue this? Any advice?
We performed a Surface finish run on a capability run. 300+ pieces sampled to get 125 pieces (25 sets of 5). Ford Requires a PPK of 1.67 on these and control.
When we crunched the data in Minitab, we got a PPK of 17.85 but we had a control point out on the R chart of the required 6-pack.
I complained because the control limits are so tight because of the very limited amount of variation in the machining process. The span of the control limits is less than the unit of measurement (RZ) and the sigma is less than the resolution found in the MSA. He didn't buy it. He said I had to remeasure, but I balk because I know that I am simply in the noise zone of the measuring process.
How do you guys argue this? Any advice?