Let’s face it, some people are better workers than others. Just like it was in high school, people can be graded as A, B, C, and D players at work. It’s been said that in management, A players want to work with A+ players, and that B players want to work with C players.
You only want to have A players in management. If you accidentally promote or hire a B player to management, after a period of time you need to sit down with them and transition them to a non-management position if you cannot get them to raise their game.
Fire the D players swiftly. You don’t want any of them on your team at all. However, C players are a different story. You want them to become B players. Be fair to them; sit down and spell out exactly what your expectations of them are. Give them a reasonable chance to improve, working with HR to document the process. Let them know that B players are the minimum that your organization can tolerate and support. They will grow to become the backbone of your organization.