They don't hear them at all if possible, instead letting them pile up endlessly, unless the employee either goes to HR or files labor charges.
Then and if, they are finally heard at the local level, they are withdrawn as "a matter of record".
My Local is entrenched in a "quid pro quo" relationship with the Company Labor Department.
The agents simply aren't literate enough, or smart enough, to formulate viable arguments on legitimate grievances, so they squash these grievances locally in hopes of consideration on discharge cases.
This is how they create the illusion that they are effective in their jobs, as nobody stays fired, but in turn very few are ever validated when grieving the Company.
Slowly, those with the fortitude to file, don't anymore, feeling it's futile.
~Bbbl~[emoji769]