Demonstration Test Plans
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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.

Dialog box items

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.

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.

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