Part of the difficulty with harvesting institutional knowledge from someone who is retiring is capturing the “feel” component.
Once you have been in a job for some time, you develop a feel for what to do. It’s hard to quantify, and it’s hard to explain to others. If it were easy then somebody would have created a spreadsheet to capture it by now. None exists.
So, the problem ends up being that we allow the feel for how to do certain work slip out the door just after the grocery store retirement cake has been consumed.
Passing along institutional knowledge is difficult, but probably the most difficult part is passing along the feel. Are you interested in capturing the feel? I hope you are. Feel is the bedrock that supports the rest of the knowledge.
Here’s an idea. This idea presupposes that you have already established some kind of mentoring program. If you haven’t, start there. If you have, then have “mentees” do this: Ask more questions that invoke reflection.
It’s a small tweak, but an important one. Reflection. It’s where all the juice is. Those about to retire have a lifetime of experience. From them we don’t need to know in detail how they handled a past situation, but how they thought about the solution. Go after the philosophy, not the tactics.