Most of the components of which successful operation on demand is a crucial factor of safety are in standby mode. Generally it is very difficult to detect the failure of standby components since their operation cannot be observed. Periodic testing is currently the only mean to cope with this uncertainty. In this study, a concept of a monitoring method for standby safety components is proposed in order to raise its availability. Basically, availability of a standby component can be improved by monitoring some detectable random failures and avoiding possible aging caused by actual operation tests.