As the (unwilling) recipient of TQM / BPR and Lean, and having the misfortune to meet some of these "Six Sigma Black Belts" ego's....read failed estate agent /used car salesman here....same capacity to produce utter bolleaux...I would like to dump every one on the ramp, in January, in lousy wx, at night and with a double brake change, toilet defects, galley defects and a u/s APU on three different aircraft....just to prove that you can't apply the principles to maintenance / rectification.
Ironic really that Motorola who promoted the system used to produce radio's etc that were the equivalent of the end product of a chicken vindaloo with 6 onion bahji's and four pints of Guiness.