What is the best way to discipline the employee causing the company into negative impact.?

The penalty , but we should know why

while firing can be tempting, it cant always be the answer. so I would either lessen their salery if possible or cut off their precentage of reward . I could also distance them from fellow members in a team to not couse furthermore impacton others, again if possible. but nevertheless negative emotions come from somewhere, so try to ask for his reasons even if they dont excuse what he did, and solve that problme first and lecture them to be professionally second