Expected Failure Time Plot

When a reliability life test is planned it is useful to visualize the expected outcome of the experiment. The Expected Failure Time Plot (introduced by ReliaSoft in Weibull++ 8)provides such visual.

Background & Calculations

Using the cumulative binomial, for a defined sample size, one can compute a rank (Median Rank if at 50% probability) for each ordered failure.

As an example and for a sample size of 6 the 5%, 50% and 95% ranks would be as follows:

5%, 50% and 95% Ranks for a sample size of 6. 

Order Number	5%	50%	95%
1
2
3
4
5
6