This is an interesting article from Economist.com about the Japanese way of getting out of your office and about having a look at what is going on in the plant.
I like the part in which the author tries to compare the Japanese way and the American way. In my opinion, there is not much point in doing that. The best is to review what the strengths of both approaches are and build an even better system from there.
If you want to be an effective manager, you need to have a hands-on approach!