Launch the Fit Life by X platform by selecting Analyze > Reliability and Survival > Fit Life by X.

Identifies the time to event (such as the time to failure) or time to censoring. With interval censoring, specify two Y variables, where one Y variable gives the lower limit and the other Y variable gives the upper limit for each unit. For details about censoring, see the Life Distribution chapter in this guide.

Identifies censored observations. By default, 1 indicates a censored observation and 0 indicates an uncensored observation in your data table.

Determines the relationships between the event and the accelerating factor. Examples include transformation using the following acceleration models:

If you select Location or Location and Scale, a message might appear stating that “Analysis must exclude groups that are all right censored to continue Nested Model Tests. Do you want to continue?” Click Yes to continue the analysis. Right censored groups indicate groups where all observations are right censored. The message does not appear if your sample data does not include right censored observations.

See Custom Relationship if you want to use a Custom relationship for your model.

Specifies one distribution (Weibull, Lognormal, Loglogistic, Fréchet, SEV, Normal, Logistic, LEV, or Exponential distributions) at a time. Lognormal is the default setting.

Displays the method for computing confidence intervals for the parameters. The default is Wald, but you can select Likelihood instead. The Wald method is an approximation and runs faster. The Likelihood method provides more precise parameters but takes longer to compute.