Quality and Reliability Methods - SAS

250 Lifetime Distribution II Chapter 14
Navigating the Fit Life by X Report Window
Results
Statistics
The Results portion of the report window shows detailed statistics and prediction profilers that are larger
than those shown in the Comparisons report section. Separate result sections are shown for each selected
distribution.
Statistical results, diagnostic plots, and Distribution, Quantile, Hazard, Density, and Acceleration Factor
Profilers are included for each of your specified distributions. The Custom Estimation tab lets you estimate
specific failure probabilities and quantiles, using both Wald and Profile interval methods. When the
Box-Cox Relationship is selected on the platform launch dialog, the Sensitivity tab appears. This tab shows
how the Loglikelihood and B10 Life change as a function of Box-Cox lambda.
For each parametric distribution, there is a Statistics outline node that shows parameter estimates, a
covariance matrix, the confidence intervals, summary statistics, and a Cox-Snell Residual P-P plot. You can
save probability, quantile, and hazard estimates by selecting any or all of these options from the red-triangle
menu of the Statistics title bar for each parametric distribution. The estimates and the corresponding lower
and upper confidence limits are saved as columns in your data table. Figure 14.12 shows the save options
available for any parametric distribution.
Figure 14.12 Save Options for Parametric Distribution
Working with Nested Models
Nested Model Tests are included, if this option was checked in the launch window of the platform.
Figure 14.13 shows Weibull Statistical results, Nested Model Tests, and Diagnostic plots for Devalt.jmp.
Separate Location and Scale, Separate Location, and Regression analyses results are shown by default
for the Nested Model Tests. Regression parameter estimates and the location parameter formula are shown
under the Estimates outline title, by default.
The Diagnostics plots for the No Effect model can be displayed by checking the box to the left of No Effect
under the Nested Model Tests outline title. The red triangle menu of the Statistics outline title provides
options for you to save probability estimates, quantile estimates, and density estimates to your data table.
If the Nested Model Tests option was not checked in the launch window, then the Separate Location and
Scale, and Separate Location models are not assessed. In this case, estimates are given for the regression
model for each distribution that you select, and the Cox-Snell Residual P-P Plot is the only diagnostic plot.