Quality and Reliability Methods - SAS

Chapter 14 Lifetime Distribution II 249
Navigating the Fit Life by X Report Window
the probability reads 0.5. From viewing Figure 14.10, where the Probability is set to 0.5, you find that the
quantile for the failure probability of 0.5 at 45 degrees Celsius is 13943.92 hours. So, at 10 degrees Celsius,
you can expect that 50 percent of the units fail by 13943.92 * 17.42132 = 242921 hours.
Figure 14.10 Weibull Quantile Profiler for Devalt.jmp
Comparison Criterion
The Comparison Criterion tab shows the -2Loglikelihood, AICc, and BIC criteria for the distributions of
interest. Figure 14.11 shows these values for the Weibull, lognormal, loglogistic, and Fréchet distributions.
Distributions providing better fits to the data are shown at the top of the Comparison Criterion table.
Figure 14.11 Comparison Criterion Report Tab
This table suggests that the lognormal and loglogistic distributions provide the best fits for the data, since
the lowest criteria values are seen for these distributions. For a detailed explanation of the criteria, see
Table 13.1 on page 220 in the “Lifetime Distribution” chapter on page 207.