Dear All,
Imagine a system consisting of 2 components in series with the same following parameters:
mtbf = 1000 h
mttr = 5 h
Knowing that A = mtbf / ( mtbf + mttr ), we have :
A1 = A2 = 1000/ (1000+5) = 0,995024876
Because they are in series A system = A1 * A2
and then A system = 0,990074503...