The comment in the Delphi post the other day about looking lean versus actually being lean solicited more than the usual number of emails. It seemed to trigger a new thought process in quite a few people – me included. I think that much of the problem lies in how few lean experts are actually manufacturing experts.
Ask anyone – including the lean experts – what Henry Ford contributed to manufacturing, and they will all answer "the assembly line". Ask what else, and you will typically get silence. Then read what Ohno and Shingo had to say about Henry Ford:
"I think that if the American king of cars were still alive, he would be headed in the same direction as Toyota" -Taichi Ohno
"The Toyota System is not a system opposed to Ford System, but rather enlarged and progressed the Ford System" – Shigeo Shingo
Ohno told Norman Bodek that he learned all he knew about the Toyota Production System from Henry Ford’s book, Today and Tomorrow. While that was certainly a gross exaggeration, the Toyota people were clear that Henry Ford began lean manufacturing.
Yet you can read Ohno and Shingo’s books all day and not find a single reference to assembly lines. So if Toyota took core lean principles from Ford, and those core principles are not assembly lines, how come we haven’t had an avalanche of literature about those principles? How come we have all been told that Ford manufacturing was the assembly line?
I think it is because the bulk of the lean literature has been provided by academic folks and consultants who are long on book learning, when it comes to lean, and short on real manufacturing experience.
I was in a factory a few weeks ago that made a consumer product, the core of which included a couple of small, precision ground parts, an electric motor and injection molded plastics. They had worked their way through three different lean consulting firms, yet they conceded that after all of the disruption and expense, their bottom line still wasn’t much different, if any, than it would have been without all of the lean effort.
Their assembly processes looked as lean as could be. They had U shaped cells, kanbans and were working very hard on their ability to change over from assembling one product to another. Their quality was very good. What was glaring by its absence, however, was similar evidence of lean in the back of the factory where machining, injection molding and motor winding happened.
Manufacturing people know that assembly is no big deal. I will get hammered by dozens of assembly managers and engineers for that statement but that plant, like most others, lives and dies with core manufacturing. If machining, molding and motor winding do their jobs in a quality manner and all of the ancillary parts arrive on time, assembly is easy. If machining screws up, however, assembly flow and quality go south in a big hurry. 70% or more of the cost, investment and defect opportunities in most companies happen in similar core manufacturing operations.
Those with little knowledge of manufacturing zero in on assembly processes. The popular press in 1914 was amazed at Ford assembly lines. And it is kinda cool to see cars coming together out of nowhere right before your eyes. Historians, journalists and many academic folks seem to latch onto this fairly labor intensive, highly visible aspect of manufacturing.
On the other hand, machining operations, winding and dipping motors and getting consistent control of molding machines is messy and complicated and far too technical for any novice to stroll in and master. Besides, it happens in back rooms on noisy machines in which the parts are hidden from view. When the doors close on a CNC milling machine and coolant starts spraying, it is impossible for a non-expert to understand what is going on in there, and which are the key variables that must be optimized to do the job well.
The answer to the rhetorical question about Ford and his contribution to Toyota is that the early Ford system mastered creating a continuous one piece flow of parts through extraordinarily difficult operations, including machining, sheet metal forming and electrical sub-assembly with near perfect quality in a very short cycle time. The much ballyhooed final assembly line was not really a big deal to Ford management at the time. It was only after the non-manufacturing public became enthralled that Ford managers talked much about it. Ford made a ridiculous amount of money because his managers mastered flow and quality in their core manufacturing activities – not because of assembly lines.
Another extreme example is a Frito-Lay potato chip plant I once visited. I could probably give them some good suggestions about the operation at the tail end where the chips were bagged and boxed in pretty Frito-Lay logo containers. However, everything I know about sorting, moving, slicing and frying potatoes in a continuous flow that yields a high quality product can be written down on the head of a pin. There is nothing of any substance I can contribute to their core, which is where all of the money is. My lean advice to them would be pretty superficial.
My point is that implementing cell production and kanbans in visible, tail end manufacturing processes is not particularly challenging, nor does it have much impact on the bottom line. The lean game will be won or lost, however, in core production areas and most so called experts do not really know enough about those areas to be of much help to you. In the end, I think that your own experts in your core manufacturing technologies are either going to make lean happen or not for your company, rather than consultants who proclaim competence in every manufacturing environment
If I were you I would cast a wary eye at any lean consultant, or the author of any lean manufacturing book, who is long on advice about assembly and thin on first hand experience in your core area.