Knowldege retention - Proactive vs. recovery?

With high turnover and difficulty in replacing key employees, knowledge retention is becoming more and more important.

I classify knowledge retention efforts into three categories:

1) Proactive – as an everyday task, capturing knowledge on an continual basis
2) Salvage – When you know someone is going to leave, capture essential knowledge in the time allotted.
3) Recovery – Finding or reconstructing the needed knowledge afterward

In an ideal world being proactive would be the best. However, capturing knowledge takes time, effort, and resources. There’s a fine balance between the value of knowledge captured and resources required. Prioritization and most importantly an understanding of “mission critical” or “position critical” knowledge is a good place to start.