My workplace, as with every one, has an annual employee review process. The whole process is a farce as the results are evaluated and changed to make sure certain special groups score the same results as everyone else.
I worked for two places that had nearly identical 1 to 5 scale scoring systems for their reviews. At both places the HR person would always start by explaining the system (everyone starts at a 3 in each evaluation area and nobody gets a 5).
At my first job for my first 18 months I was never late nor did I take any days off except for my two weeks of mandatory vacation. When my review came and the HR person gave me a 4 on attendance, I asked if we could review my attendance, use of sick days, etc. She agreed I had perfect attendance but still, nobody ever gets a 5.
They play a game so everybody ends up averaging roughly the same score so it becomes impossible to distinguish the great employees from the marginal and bad ones.