Continue assessing people throughout their tenure. As you get to know your people better, you will be better able to train and direct them. Most importantly, you will be able to assess their core values and abilities more accurately and make sure they complement yours. Don’t rest with your initial evaluation, however. Always ask yourself if you would have hired them for that job knowing what you know now. If not, get them out of the job.

Evaluate employees with the same rigor as you evaluate job candidates. I find it puzzling that interviewers freely and confidently criticize job candidates without knowing them well but won’t criticize employees for similar weaknesses even though they have more evidence. That is because they view criticism as harmful and feel more protective of a fellow employee than they do of an outsider. If you believe that truth is best for everyone, then you should see why this is a mistake, and why frank and ongoing evaluations are so important.
