BIG numbers in vinyl on the side of the machines. A BIG table of machines in the eye line of the operator.
Referring to the machine by number only (not The Big One or The Trotec or The Red One) and using that numbering system in your documentation for operations is the key.
You have no idea how much money has been lost in Chinese semiconductor factories getting this stuff right 
I most recently worked in a brand-new, state-of-the-art car factory. The British architects used a matrix method of numbering - using the building construction elements - pillars - as the basis (this is very common in large open areas like warehouses, factories, hangars). The Japanese robotic/electrical engineers that came and outfitted the factory used a different numbering system, because they did their design on spec before the construction of the buildings and won the contract, and rather than change their design, they just shoehorned it in.
The company I was hired by used a third numbering system, because the Czech data engineers laying the 300km of fibre-optic cable, putting in the data cabinets and the ‘street furniture’ (big outdoor cabinets like the phone company use on the street) didn’t have factory matrix numbers when outside the building - they have some incredible tech that allows a car to self-drive itself to a park, then load itself on a train according to orders. A distribiutor in Poland orders ten cars for stock and fifty custom builds. The train arrives at the siding and the doors on the wagon opens. The stock units start themselves, and make their way from carpark B to the train, load themselves and turn off. The custom ones are JIT (Just In Time) and should arrive fresh from final QC just as the other ones are loaded, make their way to the train and load up. The train is hooked back up to a loco and heads off to Poland. All that requires cables laid in the tarmac, controllers, cameras, etc. and they used the numbering system of the controlling software.
As you can imagine, it’s a bit of a nightmare trying to find a particular component the system tells you is giving a fault. ‘Walking the wire’ was a 13km circuit. Going the wrong direction because the wrong suffix was attached to the problem log could mean half a day of not loading cars onto transports.
Get it right, at the beginning, by getting every stakeholder’s buy-in, is my recommendation.
That the car industry makes this same decision time after time is due to the very siloed nature of the car industry - everything is devolved, everything is lowest-cost, everything is run by accountants who don’t understand anything about car plants.
It’s amazing more people don’t die on the roads