Close this search box.

Moving Average/Moving Range Chart Help

The moving average/moving range chart (MA/MR) is used when you only have one data point at a time to describe a situation (e.g., infrequent data) and the data are not normally distributed. The MA/MR chart is very similar to the Xbar-R chart. The only major difference is how the subgroups are formed and the out of control tests that apply. The steps in constructing the moving average/moving range chart are essentially the same as the Xbar-R chart.

Subgroup Formation

The MA/MR chart reuses data. For example, the data below shows the accounts receivable for each week. The data could be regrouped into subgroup sizes of three and analyzed using a MA/MR chart. The first subgroup for the MA/MR chart is formed using the first three results (for the weeks of 1/6, 1/13, and 1/20). The second subgroup for the MA/MR chart uses the weeks of 1/13 and 1/20 and then adds in the week of 1/27. The data for weeks 1/20 and 21/27 are reused in the next subgroup. This continues for each of the remaining samples. This approach allows you to plot a point with each new data point instead of waiting for three data points to form a subgroup.

Data Entry

This example will use the accounts receivable data above. You enter the data are entered into a worksheet as shown below The data does not have to start in A1. It can be anywhere on the spreadsheet. The data can be in rows or in columns. In the example workbook, the data starts in cell A10 as shown below.

Creating a New MA/MR Chart

This is all that is needed to make the chart. If you select OK at this point, the software will generate the chart using the default options. Simple and quick.

The options on the input screen are:

Options for the MA/MR chart

On the input screen above for the chart, there is a button labeled “Show Options”. If you select that button, the input screen will show the options available for the chart. It is not required to select any of these options.

Each option is described below.

Out of Control Tests

If you select the Out of Control Tests, the input screen, Tests for Out of Control Points, is displayed below.

Since the data are re-used on the moving avearge/moving range chart, there is only one option for out of control points.

Control Limit Options

f you select the “Control Limit Options” button, the following is displayed.

The options include:

Note: the additional lines, check for trends and target for average options apply only to the moving average chart.

Titles and Formats

If you select the “Title and Formats” button, the following screen is displayed:

The options include:

Manual Control Limits

If you select the “Manual Control Limits” button, the following screen is displayed:

The options include:

Chart Location

If you select the “Chart Location” button, the following screen is displayed.

The options are:


Updating the MA/MR Chart with New Data

The chart can be easily updated with new data after it has been added to the spreadsheet. Please see Updating Control Charts with New Data to see how the software finds the new data and updates the chart.

Changing the Options for the MA/MR Chart

You can change the current options for a chart (e.g., adding a Box-Cox transformation) by selecting “Options” on the Updating/Options panel on the SPC for Excel Ribbon.

The list of available charts in the workbook will be displayed. Select the chart you want to change options for. The input screen for that chart will be shown and changes can be made. See Changing Chart Options for more information

In addition, once a chart is made, there are numerous actions you can take on the chart including splitting control limits, removing points from the calculations, adding comments, selecting the range on which to base control limits, etc. Please see Control Chart Actions for details.

Scroll to Top