Читать книгу System Reliability Theory - Marvin Rausand - Страница 126

Reconsider a light bulb, similar to the one in Example 3.4, but assume that the light bulb is very seldom switched on and that it each time is energized for a short time period. The bulb may also fail in passive state (e.g. due to vibrations). A failure in passive state is not observable and leaves a hidden fault. The hidden fault is not revealed until the light bulb is switched on next time. The time of the occurrence of the failure is unknown. When we try to switch on the light and observe that it has failed, we only know that the failure occurred in the time interval since the preceding use of the light bulb. (In this example, we assume that the switch is functioning without failure.)