In safety-critical applications, such as aerospace, automotive, medical, and industrial control systems, the occurrence of faults can have serious consequences, including loss of human life, property damage, and environmental damage. For this purpose, fault occurrence is a critical concern in these applications. It is crucial to prevent defects from arising in the first place, but it is equally necessary to detect and reduce the faults when they do arise. This is accomplished by using a combination of fault-tolerant architecture, redundancy, and error detection and correction systems in both hardware and software designs. Typically, measures like the probability of failure on demand (PFOD), the probability of dangerous failure per hour (PFH), or the safety integrity level are used to quantify fault occurrence in safety-critical systems (SIL).