Carillon Technologies Limited  Individual and Moving Range Control Charts

Control Charts for Individuals:

• A traditional X/R chart does not apply to all situations requiring a variable control chart, such as the monitoring of the fountain solution pH, conductivity, or the charting of color proof densities.
• These processes typically generate just one sample data point per time period.
• A solution to this problem is the use of a control chart for individuals and a moving range.

STEPS FOR INDIVIDUAL & MOVING RANGE CHART

Step #1. Collect the data. (Collect at least 15 points.)

Step #3. Find the range for each set of two points.
The completed calculated data set looks as follows:

Step #4. Find the overall average and the overall moving range and standard deviation a) Overall average Uncoded = 5.6 + 20 = 25.6 mm
b) Overall moving range =
c) Standard Deviation

Step # 5. Compute the control limit lines. a) Individual control chart
Corn Flake Example
b) Moving range
Corn Flake Example

Step #6.

Construct the control chart by plotting the individual and range points.

Step #7.

Perform an analysis to determine if any assignable causes are acting on the data.

Step #8.

Take corrective action to bring the process into statistical control.

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