JG makes a very good point....
LEAN may well have worked for Toyota, however that's the Manufacturing Industry - our game is vastly different and to me, is not conducive to LEAN being the be-all and end-all.
In a perfect world of predictable repetitive tasks....LEAN concepts might work fine. One can schedule the entire process and foresee problems way ahead of time.
Aircraft maintenance and repair seldom works like clock work....and schedules are more like running hands over crystal balls and whistling a favorite tune.
One commerical outfit I worked for determined (how is up to question) that we could get a Bell 212 Tailboom AOG'd into Nigeria and thus did not need to keep a built up spare. End result....one aircraft AOG'd for eleven weeks awaiting that very component. Took them about a month to discover what a bad decision that was....although they would never admit it.
Never mind the peasants telling the Lords that was a real disaster in the making.....what did they know after all.
Yep....LEAN works.