Do you think that if this information was readily available, users would stop actually doing scheduled maintenance because the system reads 'ok'?
The testing procedure depends on who makes the rules and who does the work. A maintenance person making the rules doesn't have authority to shut down operations to do a live test and won't get paid overtime to do the test after hours. However, a maintenance manager who has a management level worker who doesn't get paid extra for call-ins, might (and did) make a rule that a live test be carried out before regular hours, weekly, for one hour. What is predictable is when the generator doesn't work, the maintenance log will show the system said it was okay.
