Читать книгу System Reliability Theory - Marvin Rausand - Страница 124

Consider an electric driven water pump. The essential function of the pump is to pump water at a certain rate. Assume that the target rate is 100 l/min, with performance criterion saying that the rate need to be between 95 and 105 l/min. In case of internal fouling, the pumping rate may decrease such that the performance criterion is no longer met. When the rate passes the lower threshold rate, a pump failure occurs and the pump has to be stopped. The pump remains in this state until it has been cleaned/repaired. This process is illustrated in Figure 3.3.

Figure 3.3 Illustration of the difference between failure and fault for a degrading item.