Use Parametric Growth Curve to analyze data from a repairable system, in order to estimate the mean number of failures and the rate of occurrence of failure (ROCOF), also called the repair rate, over time. A repairable system is one in which the parts are repaired instead of being replaced when they fail. For example, automotive engines are usually repaired many times before being replaced.
Use the estimated growth curves to examine the failure rate and the expected cumulative number of failures as a function of time, and to determine whether a trend exists in times between successive failures. For example, you can determine whether system failures are becoming more frequent, less frequent, or remaining constant.
For more information on growth curves, including the power-law process and the Poisson process models, go to Estimating parameters for growth curves.
To perform a parametric growth curve analysis, choose.
If you cannot make assumptions about the distribution of the cost or the number of repairs in the system, use Nonparametric Growth Curve.