The dispersion chart shown in the Measurement Systems Analysis platform is either a Range chart or a Standard Deviation chart. The Range chart plots the variability statistic for each combination of the part and X variables. The Standard Deviation chart plots the standard deviation statistic for each combination of the part and X variables. Both of these charts help you check for consistency within subgroups. In a Range or Standard Deviation chart, data within limits is desirable, indicating homogeneity in your error.
The Range Chart or Standard Deviation Chart red triangle menu contains the following options:
Show Average Dispersion
Shows or hides the average range or standard deviation on the chart.
Show Connected Points
Shows or hides lines connecting all of the ranges or standard deviations.
Show Control Limits
Shows or hides lines representing the Upper Control Limit (UCL) and the Lower Control Limit (LCL) and labels those values. For more information about the calculations of the limits used in the Range Chart, see “Statistical Details for XBar and R Charts”. For more information about the calculations of the limits used in the Standard Deviation Chart, see “Statistical Details for XBar and S Charts”.
Show Control Limits Shading
Shows or hides shading between the UCL and LCL.
Show Separators
Shows or hides vertical lines to delineate between the X variables.
Tip: You can replace variables in the Range or Standard Deviation Charts in one of two ways: swap existing variables by dragging and dropping a variable from one axis to the other axis; or, click a variable in the Columns panel of the associated data table and drag it onto an axis.