🚀 go-pugleaf

Myth #1:  For years I have heard reference to a "famous" study done Ford
(?) on transmissions(?).  One version of the story goes:  Ford and Mazda
were both using an identical (in design) transmission.  However, Ford
had far more complaints about the performance of their transmission than
Mazda reportedly did.  Some at Ford thought the difference was due to
perception; consumers just thought that Mazda had a better transmission
and so they didn't complain as much.  Others thought there might be a
physical difference.  So they obtained several of each transmission and
proceeded to measure various dimensions.  To Ford's surprise, their
transmissions had all measured dimensions in tolerance, however, the
variation took the entire tolerance range in every case.  The Mazda
parts were uniformly distributed very tightly around the target - the
Mazda parts showed very little variation.  Ford thus concluded that it
wasn't simply conformance to tolerances but reduced variation around the
target that caused high quality and happy customers.  (This story is
also promoted as one of the seeds for the six sigma movement)

Although I have heard this story innumerable times, I have never seen
the published study.  I have seen references to references, etc.  My
question is:  Is this just one of those "myths" or "parables" that gets
handed down and around or did this study ever actually occur?  If so,
where was it published?

Myth #2: I also recall a similar story concerning televisions.  The
players are usually sited as being Sony and some American manufacturer
(GE perhaps?)

Myth # 3:  And while I'm at it:  there is also a paper that supposedly
was published by someone at Motorola that stated that product that was
reworked had a much higher failure rate in the field than product that
was "built right the first time" or at least never rejected and
repaired.  ( This is also touted as a beginning of the six sigma
movement)

I appreciate any light that any one can shed on these myths.  Are they
real?  If so, where were they published?

Bev Daniels
bd1042@warn.com
danielsb@warn.com