You have an employee who is making mistakes on a regular basis and you want to take drastic action to fix the situation. Before you do, I would encourage you to ask one question “Are they making mistakes up out of fear?” Are they a good employee who isn’t making the right decisions because they’re scared of messing up? Have you created an environment where that fear is causing unforced errors? Employees making mistakes out of fear don’t need more fear, they don’t need you to scare them further, they need to know that they’re wanted. Screwing up out of the fear of making a mistake is bad leadership because it’s wasted potential.  If someone makes mistakes because they didn’t care enough or didn’t work hard enough,  that is on them and they should be corrected, but if it is out of fear that is on you.  You could have a great employee who is not living up to their talents.  This not to say you shouldn’t push people for their best, but make sure you aren’t pushing them to mistakes.  A little humble reflection may help you.