Certain companies require their managers to rank workers in the groups they supervise from best to worst, giving each worker a unique ranking based on job performance  The top 10 percent of the workers in each group are rewarded and the bottom 10 percent are penalized or fired  But this system is unfair to workers  Good workers could receive low rankings merely because they belong to groups of exceptionally good workers
Furthermore, managers often give the highest rankings to workers who share the manager' s interests outside of work
Some companies require their managers to give unique rankings to the workers they supervise.