Having experienced lean in civvy street to quite some depth I feel I can say "THERE IS NO PLACE FOR IT IN MILITARY AVIATION ENGINEERING"
Lean is about increasing productivity, cutting waste, having less WIP, and maximising throughput.
There is bugger all in there about flight safety, best effort engineering, and doing it right. If they wanted an efficient production life for repairing aircraft they shouldn't be losing all the skilled fitters and putting half trained monkeys in place because its cheaper and saves 0.17% on the bottom line of the spreadsheet. The RAF tg 1 and 2 already do a much better job than if they got in a lean consultant to balls it all up !!!