A lot of companies underestimate the effect of the exit interviews. Don’t now the reason but it is probably because of lack of HR experience or lack of time.
The exit interview is a great source of information.
When someone is leaving is always a problem for the company. It doesn’t matter if the employee is leaving for good or was forced to do it. It is an experience and the management must extract the best of it and to use it for the improvement of the organization.
The interview could be conduct immediately or could be postponed for 2-3 months so the employee will be more honest and will give useful feedback.
It is always good to catch up with a good employee and to check if he is doing or not doing well and to try to bring him/her on board again – nowadays people rarely burn bridges.
The process must be run by professional who know what to ask and how to do it in a good way having in mind that this is a sensitive moment. Some organizations use online or offline anonymous questionnaires so they can get fair information. But it is always better to have face to face meeting.