Introduction to reliability analysis

Every real-life system has a capacity (or resistance) for doing something and is subjected to some sort of demand (or load). Both capacity and demand may change depending on various factors and those factors can be viewed as random variables. When demand exceeds the capacity of the system, a system failure is reached, given that the system cannot offer the service that it was designed to provide. While some system’s failure can be permanent, other system’s failure can be only temporary. Here are a few examples of real-life systems and some of the factors that could influence their capacities and demands: