Kurt
http://performance-appraisals.org/Bacalsappraisalarticles/articles/pyr.htm is the only half decent link I could find.
In a nutshell here’s how I see it…
With a traditional business management structure you have the CEO dictating how everything is done, his/her orders are then cascaded down the line all the way to the poor grunt on the front line who has to do what he’s told, irrespective of how good or bad those orders are and how they affect the customer. Often senior management becomes so detached from the “real world” they lose track of what’s actually important and usually end up firefighting problems of their own making.
One example of this is trying to improve effciency of a manufacturing unit - typically management will dictate all sorts of ideas to the front line and while they may work sometimes, the methods used can be counter productive, unpopular and restrictive, and this leads to frustration in the workforce and ultimately the negative aspects reach the end customer - not good!
This is normally called “top down management”.
Enter the inverted pyramid…
Let’s turn things upside down. Instead of “do what I say” management now asks the front line grunts “how can I help you do your job better?”. The idea here is that the front line staff know what they need to do the job better, they know the everyday problems they face, and more importantly they interact with customers day in day out and they know what issues affect them. The management listens and provides the right tools for the job and the business improves as a result.
I could go on and quote loads of examples of how I saw this working but I’ll leave that for another day 
