[oxfordmale]

There are genuine low performers, however, based on my personal experience, they generally only constitute 25% of the people laid off for low performance. If management has overinflated expectations of your project, you will be a "low performer". If you happen to do badly on a project with high visibility to senior management, you will be perceived to be a low performer too, even if your delivery on other projects was brilliant. If your last project failed, often because of external factors, you will be deemed to be a low performer.

[rightbyte]

My favorite ranking dysfunction is that people who do the bear share of work or the hardest work also cause the most problems (bugs, rereleases etc), making them look bad if the judge have no clue how much they have done or how hard the task were.