Template:Aw reliable life

The Reliable Life
For the 2-parameter Weibull distribution, the reliable life, $${{T}_{R}}$$, of a unit for a specified reliability, starting the mission at age zero, is given by:


 * $${{T}_{R}}=\eta \cdot {{\left\{ -\ln \left[ R\left( {{T}_{R}} \right) \right] \right\}}^{\tfrac{1}{\beta }}}$$

This is the life for which the unit will function successfully with a reliability of $$R({{T}_{R}})$$. If $$R({{T}_{R}})=0.50$$  then  $${{T}_{R}}=\breve{T}$$, the median life, or the life by which half of the units will survive.