Exceptions

All most every company will have a defined policies for several internal departments like HR, Finance, Admin etc.. The main purpose of deriving these policies are to adhere to a standard approach across broad and to ensure that every individual is treated fairly.

Ironically, exceptions to break these policies will form a part in the policy statement. In practice, number of exceptions will always be on the higher side.

Why do we need to define a policy when we can give Exceptions?

I failed to find an answer. If anyone could, please let me know.