3.2 ELC Modeling
In the seminal paper by Bouricius et al. [16], a fault coverage factor in ELC was defined as the conditional probability that a system can recover its function successfully given that a component fault has occurred. It measures a system's capability to perform fault detection, location, containment, and/or recovery when a component fault occurs in the system.
This section describes the imperfect coverage model (IPCM) introduced by Dugan and Trivedi, as illustrated in Figure 3.1 [7]. The subsequent sections present the incorporation of IPCM in reliability analysis of different types of systems including binary‐state systems, multi‐state systems, and multi‐phase systems.

Figure 3.1 Structure of IPCM for component i [7].
The IPCM is associated with a particular system component i and has a single entry point representing the occurrence of the component fault. The model also has three disjoint exits R, C, S, representing all the possible outcomes...