Quality and Reliability Methods - SAS

Chapter 20 Reliability and Survival Analysis II 373
Parametric Regression Survival Fitting
Parametric Regression Survival Fitting
Survival times can be expressed as a function of one or more variables. If so, you need a regression platform
that fits a linear regression model but takes into account the survival distribution and censoring. You can do
this type of analysis with the Fit Parametric Survival command in the Reliability and Survival submenu,
or use the Fit Model fitting personality called Parametric Survival.
Example: Computer Program Execution Time
The data table Comptime.jmp, from Meeker and Escobar (1998, p. 434), is data on the analysis of
computer program execution time whose lognormal distribution depends on the regressor Load. It is found
in the Reliability subfolder of the sample data.
Figure 20.1 Comptime.jmp Data
To begin the analysis, select Analyze > Reliability and Survival > Fit Parametric Survival. When the
launch dialog appears, select ExecTime as the Time to Event and add Load as an Effect in the model. Also,
change the Distrib from the default Weibull to Lognormal. The completed dialog should appear as in
Figure 20.2.