You are often faced with the decision of how to react to the variation in your process. Should you investigate for some ...

As such, data should be normally distributed (or transformed) when using control charts, or the chart may signal an unexpectedly high rate of false alarms. Controlled variation is characterized by ...

Determine if any points fall outside the control limits. 5. Plot the data on the control chart and check out-of-control signals. 4. Use run tests to check for nonrandomness in process output (p447).