I once knew a Scottish lad, Stu' Lamb, ex RAF who later became the supervisor of our structures/sheet metal shop at a now defunct airline, who when working on the shop floor, once had a run in with some time and motion wallahs the company had brought in in order to improve our performance.
These tw@ts would stand next to you or behind you and study your work habits then make suggestions, most of which were utter bollocks, on how you could save time etc.
This lad became so exasperated at having this feckin shadow follow his every movement that he eventually turned to him and said "Do you know what this is?" holding up his 4x rivet gun in front of the guys face.
"yes"
"Do you see how it drives these 1/4" Monel rivets down?"
"Yes"
"Do you know what would happen if I put it against you forehead and pulled the trigger? Cos you're about to find out if you don't feck off and get the hell away from me."
Needless to say, a smatter of excrement hit the ventilation system over that but the time and motion tw@ts buggered off and never returned.
After he became supervisor a couple of years later, there was an attempt to bring in another team of these morons, he refused to allow them access to our shop. Once again there were questions raised regarding his decision but in true Scottish form Stu' explained just what he thought of their value and once again they vanished from sight.
Good lad was Stu', unfortunately now no longer with us.