Normal variation
On control chart:
Click Show mean and st devn, then drag over the normal pdf to show that:
The lower diagram translates this onto a run chart, suggesting control limits of µ±3σ for natural variation on a run chart when the process is in control. This avoids many 'false alarms' when the process is in control.
Finally select Skew distribution from the pop-up menu and note that µ-3σ is too low and µ+3σ is not high enough. Suggest transforming the data to be approximately normal before analysis.