So if you were monitoring that process going forward, say taking a daily measurement what value do you plug into the control chart? Do you have to transform each subsequent data point before you can review the result on a control chart? If so, what would you do if you were not using Minitab but manually gathering and recording the data?
You have noticed the big issue with individual measurements charts when the data is not normally distributed. If you subgroup the data, say hourly, group am and pm, so sample size is 4. Data will be normally distributed by default because of the central limit theorem. The distribution of the averages will always be normally distributed. Easy for manual recording and analysis.
So if you were monitoring that process going forward, say taking a daily measurement what value do you plug into the control chart? Do you have to transform each subsequent data point before you can review the result on a control chart? If so, what would you do if you were not using Minitab but manually gathering and recording the data?
You have noticed the big issue with individual measurements charts when the data is not normally distributed. If you subgroup the data, say hourly, group am and pm, so sample size is 4. Data will be normally distributed by default because of the central limit theorem. The distribution of the averages will always be normally distributed. Easy for manual recording and analysis.