Grouped per Configuration - Lloyd-Lipow Model

This example appears in the Reliability growth reference.

A 15-stage reliability development test program was performed. The grouped per configuration data set is shown in the following table. Do the following:


 * 1) Fit the Lloyd-Lipow model to the data using MLE.
 * 2) What is the maximum reliability attained as the number of test stages approaches infinity?
 * 3) What is the maximum achievable reliability with a 90% confidence level?

Solution

 The figure below displays the entered data and the estimated Lloyd-Lipow parameters.

 The maximum achievable reliability as the number of test stages approaches infinity is equal to the value of $$R\,\!$$. Therefore, $$R=0.7157\,\!$$.  The maximum achievable reliability with a 90% confidence level can be estimated by viewing the confidence bounds on the parameters in the QCP, as shown in the figure below. The lower bound on the value of $$R\,\!$$ is equal to 0.6691.  