Operational Testing Example

This example appears in the Reliability Growth and Repairable System Analysis Reference.

Consider two systems are placed into operational testing. The data for each system is given below. Do the following:


 * 1) After estimating the parameters, verify the assumption of $$\beta = 1\,\!$$.
 * 2) Estimate the demonstrated MTBF of the system.
 * 3) What are the projected MTBF and growth potential MTBF of the system if the delayed fixes are to be implemented?

The BD modes are implemented at the end of the test and assume a fixed effectiveness factor equal to 0.6.

Solution  The entered operational testing data and the estimated parameters are given below.



The assumption of $$\beta = 1\,\!$$ can be checked by looking at the confidence bounds on $$\beta\,\!$$ via the Quick Calculation Pad (QCP). The 90% 2-sided Crow confidence bounds on $$\beta\,\!$$ are shown next.



Since the confidence bounds on $$\beta\,\!$$ include one, then you can fail to reject the hypothesis that $$\beta = 1\,\!$$.

 From #1, the demonstrated MTBF (DMTBF) equals 33.7097 Hr. 

The projected MTBF and growth potential values can be displayed via the Growth Potential MTBF plot.



From the plot the projected MTBF equals 42.3824 Hr. The growth potential MTBF equals 62.9518 Hr.  