Scaling of the control limits

[JonasMetz]

If the dataset contains a "large" autocorrelation the control limits might not describe the natural process limits [1]. Thus, we need to be able to scale the lower and upper control limits by using an external/user-defined scaling factor. This scaling factor should have the default value 1, so that by default no scaling is active.

Would it be a major issue to include this option?

Reference:
[1] Donald Wheeler: "Advanced Topics in Statistical Process Control", SPC Press, 1995; Chapter 12 "Control Charts for Autocorrelated Data".