8.5 Single‐Phase System with PFs Having Global and Selective Effects
A PF that originates from a system component causes extensive damages to the rest of the system. A PFGE occurs when the PF causes the entire system to fail. There also exist a propagated failure with selective effect (PFSE), which takes place when the PF causes failure of only a subset of system components. This section presents a combinatorial reliability analysis method for single‐phase systems subject to competing failures considering both global and selective propagation effects .
8.5.1 Combinatorial Method
The combinatorial reliability analysis method can be described as a seven‐step procedure:
- Step 1: Define events representing states of the trigger component. Two disjoint events are defined:
- E1: the trigger component is functioning correctly.
- E2: the trigger component is failed.
Based on the total probability law, the system unreliability is evaluated as(8.41)
UR system = P system...