Abraham Lincoln told a lot of stories, usually to make a point. One of his favorites was to ask someone, "If you call a dog's tail a leg, how many legs would the dog have?" More often than not, the person he was asking would ponder the question for a moment, then answer, "Well, if you're going to call the tail another leg, I guess the dog would have five legs." Lincoln would then make his point by pointing out that, "No, dogs have four legs, and merely calling the tail another leg does not make it so."
In similar fashion, calling Modular Function Deployment a lean practice, in fact crowing about it as an "economical and customer-oriented way to build cars" in SME's Lean Directions does not make it a lean practice, economical or customer oriented. No matter how you cut it, Modular Function Deployment is something that is more aptly described as the tail end of a dog.
The nature of MFD is apparent when one reads the entire 'economic and customer-oriented' quote:
"Volvo introduced platform thinking as an economical and customer oriented way of building cars. The purpose was to achieve advantages such as shortened lead times, higher efficiency in production and frequent model changes. This, in turn, enabled increased sales and lower costs."
I can't find anything in that of particular value to a customer - just a whole lot of cost reduction gibberish. The cream of Swedish academic thinking behind MFD seem to have forgotten the basic premise of the law of averages - namely, If you put your head in the freezer and your feet in the oven, then, on average, you should be feeling pretty good. Their example is the application of modularity in a vacuum cleaner. With glorious charts and academic gobbledygook, they explain that you can put the same motor in just about every vacuum cleaner, slap different plastic on it to hide the motor, and voila! The customers all think they are getting exactly what they want.
In fact, the customer who cleans his 800 square foot apartment once a month pays for more motor then he needs, and the customer who meticulously cleans her 3,000 square foot home weekly gets far less motor than she needs. On average, however, since one got screwed on price but gets plenty of performance, while the other got screwed on performance but got a pretty good price, they combined customer base should be happy. That's the MFD theory, anyway.
The greater fallacy in calling MFD lean is that it does not really provide the economies it promises. "Shortened lead times, higher efficiency in production and frequent model changes" are possible from MFD solely because of less frequent changeovers in production. Instead of reducing setup times, MFD is nothing more than a practice designed to spread setup times over bigger batches - the very thing that got traditional manufacturers in trouble in the first place. It keeps the waste of setup time in the manufacturing process, and in the product cost. It just seeks to hide it.
Pursuit of modularity is the cornerstone of the Ford 'Way Forward' strategy, and Bob Lutz' scheme at GM. For them, it is a 'Back To The Future' deal. Detroit has been putting different sheet metal on common chassis and drive train platforms, then using marketing smoke and mirrors to try to dupe people into thinking that the cars were different for decades. MFD is just a 21st century buzzword for business as usual - at least thinking as usual.