Quality and Reliability Methods - SAS

156 Variability Charts Chapter 10
Variability Charts
Show Cell Means
shows the mean mark for each cell.
Connect Cell Means
connects cell means within a group of cells.
Show Separators
shows the separator lines between levels of the X, Grouping variables.
Show Group Means shows the mean for groups of cells as a horizontal solid line. A window appears,
prompting you to select the variables for which to show means.
Show Grand Mean
Show Grand Median
shows the overall mean as a gray dotted line across the whole graph.
shows the overall median as a blue dotted line across the whole graph.
Show Box Plots
toggles box plots on and off.
Mean Diamonds turns the mean diamonds on and off. The confidence intervals use the within-group
standard deviation for each cell.
XBar Control Limits
draws lines at the UCL and LCL on the Variability chart.
Points Jittered
one another.
Show Bias Line
adds some random noise to the plotted points so that coincident points do not plot atop
toggles the bias line (in the main variability chart) on and off.
Show Standard Mean shows the mean of the standard column. This option is available only when a
variable is assigned to the Standard role on the platform launch window.
Variability Summary Report toggles a report that shows the mean, standard deviation, standard error of
the mean, lower and upper 95% confidence intervals, and the minimum, maximum, and number of
observations.
Std Dev Chart
displays a separate graph that shows cell standard deviations across category cells.
Mean of Std Dev
S Control Limits
toggles a line at the mean standard deviation on the Std Dev chart.
toggles lines showing the LCL and UCL in the Std Dev chart.
Group Means of Std Dev
toggles the mean lines on the Std Dev Charts.
Heterogeneity of Variance Tests performs a test for comparing variances across groups. For details, see
“Heterogeneity of Variance Tests” on page 158.
Variance Components estimates the variance components for a specific model. Variance components are
computed for these models: nested, crossed, crossed then nested (three factors only), and nested then
crossed (three factors only).
Gauge Studies interprets the first factors as grouping columns and the last as Part, and then it creates a
gauge R&R report using the estimated variance components. (Note that there is also a Part field in the
launch dialog). You are prompted to confirm a given k value to scale the results. You are also prompted
for a tolerance interval or historical sigma, but these are optional and can be omitted.
Within this menu, you can request Discrimination Ratio, which characterizes the relative usefulness of a
given measurement for a specific product. It compares the total variance of the measurement with the