Stat > Reliability/Survival > Test Plans > Demonstration
Use to demonstrate that you have met a reliability specification or that a redesigned system has improved reliability. In a demonstration test, you verify that only a certain number of failures occur in a set amount of test time.
Minimum Value to be Demonstrated
Scale (Weibull or expo) or location (other dists): Choose to demonstrate the minimum scale for the Weibull and exponential distributions or the minimum location for other distributions, then enter the scale or location value.
Percentile: Choose to demonstrate the minimum percentile. In Percentile, enter a percentile. The percentile should be in units of time. In Percent, enter a percent associated with the percentile. The percent must be a number between 0 and 100.
Reliability: Choose to demonstrate the minimum reliability. In Reliability, enter the reliability. The reliability must be a number between 0 and 1. In Time, enter the time associated with the reliability.
MTTF: Choose to demonstrate the mean time to failure (MTTF), then enter the MTTF.
Maximum number of failures allowed: Enter one or more maximum number of failures your test allows.
Sample sizes: Choose to enter the number of units available for testing. Enter one or more sample sizes.
Testing times for each unit: Choose to enter the amount of time available for testing. Enter one or more test durations.
Note |
Each combination of maximum number of failures allowed and sample size or testing time will result in one test plan. You may wish to request several test plans and compare the results. |
Distribution Assumptions
Distribution: Choose one of seven common distributions: Weibull (default), smallest extreme value, exponential, normal, lognormal, logistic, and loglogistic.
Shape (Weibull) or scale (other distributions): Enter the shape (Weibull) or scale (other distributions). For an exponential distribution, Minitab assumes a shape value of one. See Specifying planning values.