Over the years installing control systems, air conditioning etc. you visit many sites.
One of my pet hates, is to see a control panel, where switches have been put in hand.
I understand you sometimes manually have to over-ride a system temporarily to make it operational, but some of these have been like it for years.
Recently I was at a school where the janitor, has reset the boiler controls every morning for the last five year and has now become part of his maintenance routine.
The most common reasons seem to be.
Never commissioned properly