A bad system will beat a good person every time.
Best efforts are essential. Unfortunately, best efforts, people charging this way and that way without guidance of principles, can do a lot of damage.
How can she put forth her best efforts when no matter how carefully she works, the item will still be defective? If no one cares, why should she? In contrast, when defects are rare or nonexistent or well explained, she understands that the management are accepting their proper responsibility, and she feels an obligation to put forth her best efforts: they are now effective.
The merit rating nourishes short-term performance, annihilates long-term planning, builds fear, demolishes teamwork, [and] nourishes rivalry and politics. It leaves people bitter, crushed, bruised, battered, desolate, despondent, dejected, feeling inferior, some even depressed, unfit for work for weeks after receipt of rating, unable to comprehend why they are inferior. It is unfair, as it ascribes to the people in a group differences that may be caused totally by the system that they work in.