Great points above regarding the shifts in the data. It looks like a batch operation, someone is adjusting a process to a target. As for the gage accuracy driving non normality; that should not be a factor for the distribution, only the bucketing. I would guess that is why there are gaps in the buckets every 5 bars.
There is a distinct…[Read more]
You could use the gage R and R (crossed) in Minitab and substitute the gages for the operators. That is provided you are confident that the operators are not contributing to the error, or you have already quantified their influence. You could also do 4 type one studies for precision and bias on each suspected device. 2 years, 6 months ago