Cyber–physical systems (CPSs) consists of a network, computation, and physical process. Embedded networks, which deliver control and sensing signal, can potentially affect CPSs performance. However, the degradation of physical system performance caused by the embedded networks is frequently oversimplified with strong assumptions. The proposed scheme effectively relaxes those assumptions in the existing works that network delays are bounded in a specific range or its distribution is time invariant. Most of the existing works on fault diagnosis and prognosis addressed the physical system fault detection and isolation, and ignore cyber network faults. A novel cyber network fault prognosis scheme is proposed to deal with both of cyber and physical system fault. It can identify when a cyber fault has occurred, and pinpoint the type of fault based on CPS system performance prediction, then, trigger resilience controller at an appropriate time to minimise the computational overhead. Thus, it can guarantee the stability of the entire CPS and substantially reduce computational overhead of the resilience control by triggering it if necessary.