The first of the ten practices to avoid is Forced Ranking:

According to Liz Ryan the idea behind forced ranking is that when you evaluate your employees against one another, you will see who is the most critical on the team and who is the most expendable. This theory rests on the premise that we can force or reports to work together for the sake of the team and when it really counts you can pit them against one another in a competitive exercise. The suggestion here is to evaluate employees against written goals and move quickly to remove non performers all the time and not just once a year.