9.2 System with Single Type of Component Local Failures
A combinatorial methodology is presented for reliability analysis of nonrepairable single‐phase systems subject to the PFD behavior. Each system component undergoes PFGEs and a single or identical type of LFs.
9.2.1 Combinatorial Method
The method involves a five‐step procedure described as follows.
- Step 1: Separate effects of PFGEs from the trigger component. According to the PFGE approach (Section 8.2), particularly (8.1), the system unreliability is evaluated as
UR system t = 1 − P u t + Q t · P u t ,
where Pu(t) = P (no PFGEs from the trigger component T take place during the mission) = 1 − qTp(t). Q(t) in (9.1) is evaluated through the following steps.
- Step 2: Define probabilistic functional dependence cases (PFDCs). PFDCs are identified to cover all possible isolation relationships between the trigger component and related PDEP‐components belonging...