Quality and Reliability Methods - SAS

Chapter 10 Variability Charts 157
Variability Charts
variance of the measurement error. Misclassification Probabilities show probabilities for rejecting
good parts and accepting bad parts. Bias Report shows the average difference between the observed
values and the standard. A graph of the average biases and a summary table are given for each X variable.
Linearity Study performs a regression using the standard values as the X variable and the bias as the Y.
This analysis examines the relationship between bias and the size of the part. Ideally, you want the slope
to equal 0. A nonzero slope indicates your gauge performs differently with different sized parts. This
option is available only when a standard variable is given.
AIAG Labels enables you to specify that quality statistics should be labeled in accordance with the
AIAG standard, used extensively in automotive analyses.
A submenu for Gauge RR Plots lets you toggle Mean Plots (the mean response by each main effect in
the model) and Std Dev plots. If the model is purely nested, the graphs are displayed with a nesting
structure. If the model is purely crossed, interaction graphs are shown. Otherwise, the graphs plot at
each effect independently.
Figure 10.5 Gauge Mean plots for 2 Factors Crossed example
Figure 10.6 Gauge Std Dev plots for 2 Factors Crossed example
For the standard deviation plots, the red lines connect
mean weighted variance for each effect.
Script contains options that are available to all platforms. See Using JMP.
The default condition of these options and others can be set by using preferences. To access the preferences
dialog, select File > Preferences from the main JMP menu bar. After the dialog appears, click the
Platforms icon on the left, and then select Variability Chart from the Platforms scroll menu.