When the watchdog goes active, it's like the "idiot light" on the dashboard of your car. It doesn't tell you any problem is likely. It merely tells you that trouble has arrived.

If the watchdog is ever activated because your firmware has failed to "kick the dog", then there's a fatal flaw in the firmware. If it times out because of a brownout or unanticipated power failure, then there's a hardware failure.

There are devices that actually recognize imminent hardware failures of this type, and allow an orderly response. With all the hoopla about supervisors these have escaped mention. They're very much like supervisors, with the exception that they monitor the pre-regulated power supply and therefore recognize when trouble is imminent. I suspect that, with a little thought, even the popular supervisor/watchdog chips can be made to do that, though possibly not with switching power supply outputs due to their excessive ripple. Even that can be taken into account, though.

RE