In the current economy, many are thinking twice about letting marginal or poor performers go. The main comments we hear pertain to the difficulty in finding a job these days. That is a noble concept, but there are times when it is best for the organization if leaders make the difficult decision. The question becomes: How long do we wait? There are certain employees who have great talent and their performance does not match their capabilities. There are others who have great talent and are solid performers but who "break glass" around the organization, keeping everyone on edge.
One way to evaluate how to deal with these situations comes from Kansas City Chiefs coach, Herm Edwards. It is the mental process he puts himself through when evaluating his players. He has a simple formula: T + P > D. T is talent, P is production, and D is the drama associated with an employee's presence. It Talent + Production are greater than the Drama associated with an individual's presence in the organization, the coach advises working to improve the individual's performance. If the math ceases to work, and the calculation changes, it is time to part company with that individual.
I had a great boss years ago who was a tough lady when necessary. We were discussing whether to keep or fire a particular professional on our staff. He was a recurring problem to the organization and ate up a lot of her time. I had suggested we wait for a while longer (for no valid reason, really) and her remark has stayed with me to this day. She said, "Mike. Better and end with terror than a terror without end."
So if T + P is > D, stay the course. Invest the time and effort to help that individual improve. If not? Don't.