Suppose you have failure times for 70 engine fans, with some of the failure times censored. You want to fit a distribution to the failure times and then estimate various measurements of reliability.
1. Select Help > Sample Data Library and open Reliability/Fan.jmp.
2. Select Analyze > Reliability and Survival > Life Distribution.
3. Select Time and click Y, Time to Event.
4. Select Censor and click Censor.
5. Click OK.
The Life Distribution report window appears.
6. In the Compare Distribution report, select Lognormal distribution and the corresponding Scale radio button.
A probability plot appears in the report window.
Figure 3.2 Probability PlotĀ
In the probability plot, the data points generally fall along the red line, indicating that the lognormal fit is reasonable.
Below the Compare Distributions report, the Statistics report appears. This report provides a Model Comparison report, nonparametric and parametric estimates, profilers, and more.
Figure 3.3 Statistics ReportĀ
The parameter estimates for the lognormal distribution are provided. The profilers are useful for visualizing the fitted distribution and for estimating probabilities and quantiles. For example, the Quantile Profiler indicates that the estimated median time to failure is 25,418.67 hours.