By adding a fifth subassembly with reliability ( R ) ( choose any value between 0.7 to 0.9 ) to redesign the network in

By adding a fifth subassembly with reliability $($R$)($choose any value between $\mathrm{0.7}$ to $\mathrm{0.9})$

to redesign the network in $($i$)$ and explain how the improvement has been made to the

overall system reliability.