Now, most companies will deal with poor performance through some sort of appraisal system, or they will go through some sort of form of disciplinary process, but all that really tends to deal with is what the problem is.

The process that should be followed is you should deal not only with what the issue is in terms of poor performance, but how they are expected to improve, and also why they are expected to improve.

What, how and why are the keys on the different elements to get them up to speed, because then they buy into the why they're doing it, they understand the goal and they understand what is required to meet that goal.