Example of the Fit Parametric Survival Platform
In this example, you fit a parametric regression model to computer program execution times. The execution time data have a lognormal distribution that depends on the value of another variable in the data table.
1. Select Help > Sample Data Folder and open Reliability/Comptime.jmp.
2. Select Analyze > Reliability and Survival > Fit Parametric Survival.
3. Select ExecTime and click Time to Event.
4. Select Load and click Add.
5. Change the Distribution from Weibull to Lognormal.
6. Click Run.
Figure 15.2 Computing Time Output
When there is only one effect, a plot of the survival quantiles for three survival probabilities are shown as a function of the effect.
Time quantiles are desired for when 90% of jobs are finished under a system load of 5. See Meeker and Escobar (1998, p. 438).
7. Click the Parametric Survival Fit red triangle and select Estimate Quantile.
8. Type 5 in the first row beneath Load.
9. Type 0.9 in the first row beneath p.
10. Click Go.
Figure 15.3 Estimates of Time Quantile
The report estimates that 90% of the jobs will be done by 571 seconds of execution time under a system load of 5.