Plant standards for your home.
On a plant, a loose connection does not just trip a breaker. It stops a production line, or it kills somebody. That is the standard I was trained to for twenty years, maintaining electrical systems at Iscor, Sasol, Impala and Anglo. Nobody there cared how fast I was. They cared that it was right.
Ten years ago I turned that on the town I live in. Same meter, same method, same paperwork — now on your DB board, your geyser, your fence. A house fault is smaller than a plant fault. It is not simpler, and I don't treat it as if it is.
So you get a man who spent a career finding faults in systems nobody could afford to replace. That is the whole difference between finding the cause and swapping parts until something works.