Quoted message said:The above reference is a mystery to me. I don't
know what variables are involved nor what a collision of
variables is.
Quoted message said:I suggest you don't use it, because it is not
commonly recognized and confuses the issue.
Jobst Brandt
Senior RBT contributor Jobst Brandt has suggested I explain or refrain
from using my so called mystery phrase, "when variables collide". Mr.
Brandt has also suggested that I may not even know what a variable is.
RBT contributors as a whole, are very talented individuals who've
enjoyed many unsung accomplishments. I feel that to chronologically
list my own achievements, would be, in general, an insult to the overall
intelligence of those who frequent RBT. Though accurate and true, out
of mutual respect I've omitted details that some may consider
self-indulging and boastful.
Characteristics is a word that can be used to describe the steps,
procedures, specifications and processes of the manufacture and assembly
of component parts. These characteristics are typically measured in one
of two ways. Either variable, meaning measurable by some definitive
manner, or attribute, meaning accept / reject by a specific standard.
From Mr. Brandt's book, the Bicycle Wheel, I'd like to site examples of
both.
Page 111, FINAL TENSIONING
(quote) Spoke tension can be measured directly with a tensiometer
[variable data] but it also can be determined by comparing the tone
[attribute data] of the wheel to another properly-tensioned wheel of the
same type. For the best ring, pluck the spokes at the nipples. By
matching the tones of the spokes they can be brought very close to the
same tension. (end quote)
Mr. Brandt has identified spoke tension as a characteristic of
assembling part components into a wheel. He's also identified that
variable data (tensiometer) and/or attribute data (the plucked tone) as
being the key characteristics of components assembled into a wheel of
maximum strength.
I coined the phrase "when variables collide" over 25 years ago. I used
those three words to open a presentation on The Concept of Variation,
Quality and Fitness for Use. The term was my simplistic way to
illustrate and reinforce the need for Statistical Process Control (SPC)
techniques in component part manufacturing and assembly. Controlling
the identified key characteristics of the process insured that the
characteristics were in control as well.
Best Regards - Mike Baldwin