Ñõåìû ñ óçëîâûìè ýëåìåíòàìè.
Âûáèðàåì óñëîâíóþ ïîäñèñòåìó ñ óçëîâûìè ýëåìåíòàìè P3 –P4
P(H1) = P3 P4
P(H2) = P’3 P’4
P(H3) = P3 P’4
P(H4) = P’3 P4
Ps/H1 
= [1- (1-p1) (1-p2)] [1- (1-p5) (1-p6)]
Ps/H2 
= 0
Ps/H3 
= P1 P5
Ps/H4 
= P2 P6
Ps = SNi=1 P(Hi) * Ps/Hi
i Î Ip – i ïðèíàäëåæèò ìíîæåñòâó ðàáîòîñïîñîáíûõ ñîñòîÿíèé.
Ps= P3 P4 [1- (1-p1) (1-p2)] [1- (1-p5) (1-p6)] + P3 P’4 * P1 P5 + P’3 P4 * P2 P6