X Median R Charts in Excel

Use an X Median R Chart to Evaluate Stability of Processes Using Variable Data

The XMedianR chart works just like the X bar R chart except that it uses the median instead of the average as a measure of central tendency.

Here is an example of an X Median R Chart created using QI Macros for Excel.

x median r chart in excel

The X Median R chart can help you evaluate the cycle time for almost any process: making a widget, answering a customer call, seating a customer, delivering a pizza, or servicing an appliance. This chart is especially useful when you do this many times a day. Collecting the data could be expensive if you measured every time you did it. Using a small sample (typically five), however, you can effectively measure and evaluate the process.

Calculate, plot, and evaluate the range chart first. If it is "out of control," so is the process. If the range chart looks okay, then calculate, plot, and evaluate the X chart.

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To create a X Median R Chart using QI Macros...
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