WingNut60 - I've worked in facilities where an impairment test is given rather than drug or alcohol testing. I think that is a very respectful approach and actually makes more sense. And that's why I included fatigue. The focus should be on fitness for duty. I can remember when drug and alcohol testing first became popular, on the back of massive campaigns from testing suppliers. Commercially drug and alcohol testing is much more lucrative than cognitive testing.
I don't underestimate the extent of alcohol and drug use in Indonesia.