This is extremely clever, and something I've never even heard of before, bravo. The closest I've ever seen to this sort of practice in the wild is periodically

This is extremely clever, and something I've never even heard of before, bravo. The closest I've ever seen to this sort of practice in the wild is periodically shifting people around so that more than one person knows how a system works. But more often I've seen no attempts at this, and a mad scramble with KT meetings when someone gives their two weeks notice. I'm expecting a similar mad scramble when I put in my two weeks at my current company (hopefully within the next two months, interviewing with various companies now).