Number of failures the power supply has experienced since the most recent insertion of the power supply and boot of the system. The number of failures for a power supply will be cleared if the power supply is removed from the system or if the system is rebooted. For non removable power supplies, the number of failures will not clear until the system reboots. Failures are any events where power delivery from the power supply did not occur when expected. This includes unsupported power supply types since their power delivery is not considered valid even though the power supply itself may not have an internal failure. Some examples of failures are over current, invalid input power, and unsupported power supply type.