The Reliability Test Plan feature computes required sample sizes, censor times, or precision, for estimating failure times and failure probabilities.
To launch the Reliability Test Plan calculator, select DOE > Sample Size and Power, and then select Reliability Test Plan. Reliability Test Plan Window shows the Reliability Test Plan window.
Reliability Test Plan Window
Interval Ratio is sqrt(U/L), the square root of the ratio of the upper and lower limits.
Two-sided Interval Absolute Width is U-L, the difference of the upper and lower limits.
Lower One-sided Interval Absolute Width is T-L, the true value minus the lower limit.
Two-sided Interval Relative Width is (U-L)/T, the difference between the upper and lower limits, divided by the true value.
Lower One-sided Interval Relative Width is (T-L)/T, the difference between the true value and the lower limit, divided by the true value.
 – estimate the time associated with a specific probability of failure.
 – estimate the probability of failure at a specific time.
After the Continue button is clicked, two additional statistics are shown:
 1 Select DOE > Sample Size and Power.
 2 Select Reliability Test Plan.
 3 Select Weibull from the Distribution list.
 4 Enter 2000 for the Weibull α parameter.
 5 Enter 3 for the Weibull β parameter.
 6 Select Two-sided Interval Absolute Width from the Precision Measure list.
 7 Select Estimate time associated with specified failure probability.
 8
 9 Enter 2500 for Censor Time.
 10 Enter 200 for Precision.
 11 Click Continue. Reliability Test Plan Results shows the results.
Reliability Test Plan Results
A reliability demonstration consists of testing a specified number of units for a specified period of time. If fewer than k units fail, you pass the demonstration, and conclude that the product reliability meets or exceeds a reliability standard.
The Reliability Demonstration feature computes required sample sizes and experimental run-times for demonstrating that a product meets or exceeds a specified reliability standard.
To launch the Reliability Demonstration calculator, select DOE > Sample Size and Power, and then select Reliability Demonstration. Reliability Demonstration Window shows the Reliability Demonstration window.
Reliability Demonstration Window
Reliability Demonstration Plot
 1 Select DOE > Sample Size and Power.
 2 Select Reliability Demonstration.
 3 Select Weibull from the Distribution list.
 4
 5 Enter 2 for Max Failures Tolerated.
 6 Enter 1000 for Time.
 7 Enter 0.9 for Probability of Surviving.
 8 Enter 800 for Time of Demonstration.
 9 Click Continue. Reliability Demonstration Results shows the results.
Reliability Demonstration Results