Methods and formulas for M-failure test plan in Demonstration Test Plan

Reliability and inverse reliability functions

Smallest extreme value

Reliability
Inverse reliability
where
TermDescription
ttime
μlocation parameter
σscale parameter
Φsev(t)CDF of the smallest extreme value distribution
Φ-1sev(t)inverse CDF of the smallest extreme value distribution

Weibull

Reliability
Inverse reliability
TermDescription
ttime
pprobability
βshape parameter
θscale parameter

Exponential

Reliability
Inverse reliability
TermDescription
ttime
pprobability
θmean parameter

Normal

Reliability
Inverse reliability
TermDescription
ttime
μlocation parameter
σscale parameter
Φnor(t)CDF of the normal distribution
Φ-1nor(t)inverse CDF of the normal distribution

Lognormal

Reliability
Inverse reliability
TermDescription
ttime
μlocation parameter
σscale parameter
Φnor(t)CDF of the normal distribution
Φ-1nor(t)inverse CDF of the normal distribution

Logistic

Reliability
Inverse reliability
where
TermDescription
ttime
μlocation parameter
σscale parameter
Φlogis(t)CDF of the logistic distribution
Φ-1logis(t)inverse CDF of the logistic distribution

Loglogistic

Reliability
Inverse reliability
where
TermDescription
ttime
μlocation parameter
σscale parameter
Φlogis(t)CDF of the logistic distribution
Φ-1logis(t)inverse CDF of the logistic distribution

Equation

The equation for an m-failure test plan is as follows:

Notation

TermDescription
αalpha (which equals 1 – the confidence level)
Rreliability or survival function at time t
Nminimum numbef of units to be tested
By using this site you agree to the use of cookies for analytics and personalized content.  Read our policy