Quality and Reliability Methods - SAS

240 Lifetime Distribution II Chapter 14
Launching the Fit Life by X Platform Window
6. Leave the Censor Code as 1. The Censor Code is the identifier for censored observations. By default, 1
indicates censored observations; all other values or missing values are uncensored observations.
7. Select Weight as Freq.
8. Keep Arrhenius Celsius as the relationship, and keep the Nested Model Tests option selected. This
option appends a nonparametric overlay plot, nested model tests, and a multiple probability plot to the
report window.
9. Select Weibull as the distribution.
The launch window lets you specify one distribution at a time, and includes the Weibull, Lognormal,
Loglogistic, Fréchet, SEV, Normal, Logistic, LEV, and Exponential distributions. (Lognormal is the
default setting.)
10. Keep Wald as the confidence interval method.
The Wald method is an approximation and runs faster. The Likelihood method provides more precise
parameters, but takes longer to compute.
Figure 14.2 shows the completed launch window.
Figure 14.2 Fit Life by X Launch Window
11. Click OK. Figure 14.3 shows the Fit Life by X report window.
Note: See “Using the Custom Relationship for Fit Life by X” on page 258, if you are using the Custom
relationship for your model.