The Type-III asymptotic distribution of the minimum value, developed by Weibull for studying the fatigue and fracture of materials, is known as the Weibull distribution. The two-parameter form is widely used in the life estimation of mechanical and electronic components. It can be represented by setting ε to be zero in the Type-III minimum value distribution is Extreme Value Distribution Value. The CDF of the two-parameter Weibull distribution is
The corresponding PDF is
For the two-parameter Weibull distribution, the mean
and the coefficient of variance are related to the parameters 
and 
as follows:
and
If the mean and coefficient of variance are known, the
parameters and can be approximated for
practical applications:
and
