From what I've seen:
LEAN and 6-Sigma were tools designed for use by large manufacturing industries.
The thing about manufacturing is that it is a "straight line process" by which I mean that "Things" come to the factory, at the point and time of their need to feed the Line, and are assembled in strict order by people who are task-trained for single aspects of the Line assembly process.
The need for LEAN was instigated by (toyota?) to strip out waste from post-WW2 production methods and cut the "Manufacturing" process to the minimum by using Time-and-Motion methods - this is now wrapped in modern glitzy business-speak and has all sorts of Forms, Terminology, Language changes and some rather weird "business" games to play whilst your doing the problem definition and solving.
I have seen it work.
Although, more often than not, I have also seen it...
1. Complicate matters because some idiots forgot to replace the old scheme with the new one (the point is to make things simpler - not to add layers of complicated additional administration)
2. Not produce anything at all, due to a lack of commitment by those attending the games!
My Point?
LEAN and 6-sigma can be a good "TOOLS" when used for the right reasons - They are not the new cure-all for all your present management's previous c0ck-ups. (I dont know the management in question so this is not aimed at them, particularly!)
But when the UK Government used it on the MoD, Civil Services and the NHS it has caused great disruption and chaos among those at the lower end of the food chain - it has almost decimated manpower levels and doubled workoads with no obvious thoughts to the safety levels / risks incurred within either organisation. It has been apparent that the only real requirement was to cut manpower in all organisations without regard to Shifts or other hard fought-for practice reasons.
Only the resultant low morale and increase in exiting manpower has helped the remuneration increase to cope with the work.
The end result?
After several long years of undirected disruption and uncommunicated chaos - and suffering from overcooked redundancy payments and low morale among the remaining workers - and whilst still in the midst of the hardships incurred, some Spin-Doctor will say how well it turned out - and its a lie!
For aircraft MAINTENANCE (i.e. not manufacturing) there are some real practicle differences:
1. No Line or Base Maintenance aircraft runs along a production line so it is not possible to tell when you will want a spare part - "Just-In-Time" practices are often "Just-Much-Too-Late"!
2. Spare parts are often removed, worked on and installed to the same aircraft. I haven't seen this work under LEAN as "Consultants" say the duff part should all be reworked in a Workshop - I dont see how this can reduce down-time when you cant get the new part "Just-In-Time"?
3. LEAN usage was seen to be devisive and targetted at Ground Trades - The reductions in manpower, because of LEAN Events, often overrode the manpower requirement from a military PoV? (Squadrons used to use the extras on Guarding, etc.) e.g. The removal of Squadron Technicians to central pools of technicians was not followed by a similar centralisation of aircrews (a logical follow-on action), and thus disengaged some loyalty and pride in work carried out.
I really hope this helps.
Rigga
Edited bit...
"From what i know the RAF have introduced it a number of years ago to great affect for cost savings in their maintenance practices"
As a personal observation: This comment is rubbish - except from a Bean-Counters Point of View! ALL RAF maintenance (dont know of RN or Army) is now in constant disarray and confusion due to the misuse of LEAN and cost-cutting excercises.
'Nuf said.
Rigga