I was flipping through a book on Controlled Flight Into Terrain (i.e. plane crashes based on pilot error--and an excellent euphemism to boot) at the book store when I saw the following illustration of the causes of CFIT:
I think it's actually a pretty brilliant description of the systematic buildup of errors that occur in almost any organization, 'cept here they lead to a big crack in your plane, rather than a bad product launch or a recall. It also shows how the fault does not just rest with the last person to have had the control stick (so to speak).
[Update: a little research revealed that the diagram was originally published in James Reason's book Human Error, which seems like an interesting general theory of error.]
I do like this. Though I think it would have been more interesting to have the "error holes" leading to the mishap be different sizes and not perfectly aligned. This is the reality of what the diagram is attempting to illustrate. It is the tiny crack of possibility resulting from non-aligned factors that will most likely be missed.