the folly of procedures

Something I've noticed, especially working with Units of Competency when I was a business trainer, is that, when you try to document work tasks and roles in words, in a thorough and systematic way, simple things become complicated. 

Documenting of a job becomes a job in itself, and the task of documenting is not always relevant or helpful. Take a simple task like making a cup of coffee. Writing a procedure that explains how to do that task is quite a difficult thing, because you have to assume that the reader doesn't know anything about making coffee. So, you have to tell them how much water to put in the kettle, and that the water will get very hot so be careful not to spill it on yourself, and there will be extra steps depending on how much, if any, sugar the person wants in their coffee, and then there's the question of milk and getting the milk out of the fridge and opening the milk, and putting the milk back in the fridge afterwards, and the whole procedure has to be repeated as many times as there are people you're making coffee for, etc

And does having that written procedure help at all with doing the task well?