The process to plot control charts is as below.
1. Collect data over a period of time.
2. Plot this on a run chart.
3. Collect minimum 30 data sets. (preferably subgroups)
4. Look for the special cause trends (7 of them in all)
5. If none of them exist then plot control limits and then calculate capabilities later on.
6. Even in the phase of…[Read more]