Don’t ignore the problem
Too often these issues go unaddressed. “Most performance problems aren’t dealt with directly,” says Weintraub. “More often, instead of taking action, the manager will transfer the person somewhere else or let him stay put without doing anything.” This is the wrong approach. Never allow underperformance to fester on your team. It’s rare that these situations resolve themselves. It’ll just get worse. You’ll become more and more irritated and that’s going to show and make the person uncomfortable,” says Manzoni. If you have an issue, take steps toward solving it as soon as possible.
Via The Learning Factor
The assumption often is that poor performance is result of some problem with the performer, but it would be wise to examine the circumstances closely because is it a common bias for people to attribute others failures to them and de-emphasize the situation factors that may be contributing. Compounding this, we as managers often are biased in seeing our own success as the result of our efforts and failures as a result of happenstance and not our shortcomings— making it still harder for us to see how we might contribute to others' poor performance.
A great article worth practical ways to improve performance. ALL managers should be coached to do this type of thing.
It's tempting to delay dealing with under performers, but they rarely improve on their own. This article provides actionable advice that works in the real world.