Consider the following three simple systems:

A single component

A parallel structure of two identical components

A $2-$out$-$of$-3$ system with identical components

All the components are assumed to have the same constant failure rate $.$ The systems

are exposed to common cause failures that may be modeled by a $-$factor model.

For a constant failure rate $=1.$ Draw the relationship between the MTTFs and the

$-$factor for the three systems.