RE: Shainin Methodology

[Marc Richardson <MRichardson@jaeoregon.com>]

Among other things, Dorian Shainin is credited with stating that there is no
such thing as assignable cause variation. At first, this would seem to be
heretical, however, if you think about it, you realize that all variation
exists on a continuum, it is not neatly dived up into two distinct camps
called random and non-random variation. Shewhart simply drew a practical
line in the sand beyond which, he said, it makes economic sense to look for
the causes of variation of a relatively larger magnitude.
Marc Richardson
Sr. Q.A. Eng