Getting the black spot
Happened to me when working for a large oil company who wanted to get rid of a number of people. They brought in a specialist "business efficiency" consultancy who interviewed most of the management team indicvidually. As far as I could ascertain the main purpose of the interviews was to dig some dirt on certain people (in fact more or less anyone) who was considered not to be "performing".
Following on from this process we were all graded A - C where A meant that the company wanted to keep you and was not going to offer you a redundancy, B was "you can stay or go" with the caveat that you may have to change role, and C was the company deemed you expendable and you would be given a [semi voluntary] redundancy.
About 30% of the workforce were graded A, another 50% were graded B [including me], and 20% were graded C.
This went really well [not] until the unions got involved. E.g. Billy the most useless operator on the planet could not be made redundant because he has a wife and children etc etc.
And so it transposed the my functional alcoholic worst operator [let's call him Reg because that was his name] got to stay. When I say functional, Reg could work when he had sobered up enough to remember his name and approximately which day of the week it was. I sent him home on at least two occasions for turning up absolutely rotten drunk and almost incapable of walking. That wasn't the first time either.
In the end I volunteered to leave and Reg got to stay, but it backfired spectacularly on the company as those grade A's who wanted to leave ended up being allowed to leave with a package and most of the grade C muppets who would struggle to find alternative employment were allowed to stay.
Leaving was actually my best career move ever.