@Lost ... Re: @big_D What's the point?
I don't work in IT. I've never worked in IT (thank goodness). I can find TDC on my car engine (and used to) but nowadays I pay a mechanic to do that sort of thing for me. If my car broke down on the road, being able to find TDC would not help me to get it started. However, I do always carry a mobile phone and have a subscription to a recovery service, which is much more useful that knowing how to find TDC.
If I was the owner/director/manager of a company that relied on a computer controlled/related production line then I'd make damn sure that there was training, procedures and processes in place to deal with common/forseeable problems and breakdowns. Perhaps you prefer the 'keen amateur' approach to running a company which clients and employees depend on?