The power of a test is the probability of correctly rejecting H0 when it is false. In a demonstration test, power is the probability of correctly concluding that you have demonstrated a goal value. You can increase the power of your demonstration test by reducing your goal value or by increasing the number of failures allowed.
If you provide the sample size, Minitab displays the testing time needed for your m-failure test. Alternatively, if you provide the testing time, Minitab displays the necessary sample size.
For the ball-bearing data, you chose to use a 0-failure test with a sample size of 3. At a 95% level of confidence, the testing time required to demonstrate that the scale of the new system exceeds 1000 hours is 998.906 hours.