8.2 PFGE Method
Til and Tip are random variables respectively representing the time‐to‐local‐failure and the time‐to‐PFGE of a system component i. fil(t) and fip(t) represent the probability density function (pdf) of Til and Tip, respectively. qil(t) and qip(t) are unconditional local and propagated failure probabilities of component i at time t, respectively. Thus,
with Pu(t) being defined and computed as
Q(t) in 8.1 is defined as a conditional system failure probability given that no PFGEs take place during the considered mission time. The evaluation of Q(t) requires...