Individuals-Moving Range Chart
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Stat > Control Charts > Variables Charts for Individuals >  I-MR

An I-MR chart is an Individuals chart and Moving Range chart in the same graph window. The Individuals chart is drawn in the upper half of the screen; the Moving Range chart in the lower half. Seeing both charts together allows you to track both the process level and process variation at the same time, as well as detect the presence of special causes. See [31] for a discussion of how to interpret joint patterns in the two charts.

By default, I-MR Chart estimates the process variation, s, with MR / d2, the average of the moving range divided by an unbiasing constant. The moving range is of length 2, since consecutive values have the greatest chance of being alike. You can also estimate s using the median of the moving range, change the length of the moving range, or enter a historical value for s.

For more information, see Control Charts Overview and Variables Control Charts for Individuals Overview.

Dialog box items

Variables: Choose one or more columns containing the observations.

<Scale>

<Labels>

<Multiple Graphs>

<Data Options>

<I-MR Options>