Quality and Reliability Methods - SAS

Chapter 14 Lifetime Distribution II 257
Viewing Profilers and Surface Plots
Figure 14.18 Weibull Distribution Diagnostic Plots for Multiple Models
You can see, from Figure 14.18, that side-by-side comparisons of the diagnostic plots provide a visual
comparison for the validity of the different models. The red-triangle menu on the Cox-Snell Residual P-P
Plot has an option called Save Residuals.
Viewing Profilers and Surface Plots
In addition to a statistical summary and diagnostic plots, the Fit Life by X report window also includes
profilers and surface plots for each of your specified distributions. To view the Weibull time-accelerating
factor and explanatory variable profilers, click the Distribution tab under Weibull Results. To see the surface
plot, click the disclosure icon to the left of the Weibull outline title (under the profilers). The profilers and
surface plot behave similarly to other platforms. See the Modeling and Multivariate Methods book.
The report window also includes a tab labeled Acceleration Factor. Clicking the Acceleration Factor tab
shows the Acceleration Factor Profiler. This profiler is an enlargement of the Weibull plot shown under the
Acceleration Factor tab in the Comparisons section of the report window. Figure 14.19 shows the
Acceleration Factor Profiler for the Weibull distribution of Devalt.jmp. The baseline level for the
explanatory variable can be modified by selecting the Set Time Acceleration Baseline option in the
red-triangle menu of the Fit Life by X outline title.