Hello Experts,
I'm doing some Cpk calculation method validation for our process versus AIAG guidelines.
Some background, I initially run 300 samples to setup a baseline using JMP - Cpk calculated is using I-MR (based on capability analysis at distribution).
Our production line is using x-bar & R-chart for n=10 for 14 batches (with 1 batch outlier).
Means, our production sample 10 measurement for each batch & SPC chart was monitored using Excel including the Cpk.
I want to show them that they should x-bar & s-chart per AIAG guideline & what will happen if they use s-chart or what would be the Cpk if the process stable.
When I ran the data with subgroup ID using JMP, the Cpk calculated is based on I-MR (photo below):
Since R-chart, s-chart or MR are just used as std. dev estimates (using formula R-bar/d2), how can I configure JMP to calculate the capability analysis using R or s when I want to?
p/s: I don't really buy to this argument on which Cpk method is correct because all method are correct based on our own process scenario/interpretation (SPC is the champion to do improvement) but AIAG put it in their guidelines, so I need to know how to calculate the capability analysis using R or s with JMP .....
Any tips very much appreciated and I use JMP 15.