Template:Nominal time to real goal

Nominal Time to Reach Goal
Assuming that we have a target MTBF or failure intensity goal, we can solve Eqn. (Nominal FI) to find out how much test time, , is required, (based on the Crow Extended model and the nominal idealized growth curve) to reach that goal:


 * $${{t}_{N,G}}={{\left[ \frac{{{r}_{G}}-{{\lambda }_{A}}-(1-d){{\lambda }_{B}}}{d\cdot \lambda \cdot \beta } \right]}^{\tfrac{1}{\beta -1}}}$$

Note that when $${{\lambda }_{I}}<{{r}_{G}}$$  or, in other words, the initial failure intensity is lower than the goal failure intensity, there is no need to solve for the nominal time to reach the goal, because the goal is already met. In this case, no further reliability growth testing is needed.