ZD - Zero Defect
Created by Phillip Crosby while working at
Martin-Marietta from 1957 to 1965, First controversial debates over the
theory started in the 1960's*, one aspect involves the concept
that all self-controlled workers have no reason to make errors, also known
as defects. If workers are appropriately motivated, they will actually
make no errors, and thus Zero Defects.
Zero Defects was seen by some groups as
being unrealistic until Six Sigma concept and 3.4 ppm or almost zero
defects was introduced.
Some companies initiated motivational
programs, under the urging of the DOD, (Department Of Defense), but some
of these undertakings consisted of little more than motivational
propaganda which had little effect on quality.
Some enhanced programs included a
suggestion styled scheme for quality improvements. That concept was
adopted by Motorola and lead to the six
sigma concept of suggestions for saving money in every process and
department measured by RONI, (return on net investment) and RONA, (return
on net assists) based on worker suggestions.
The fatal error of the hypothesis was ...
- operator errors are the main foundations
of defects
- that all operator errors can be resolved
with the proper driving forces.
While winning approval with some managers,
there appears to be no basis in fact for this theory. What the facts
indicate are that ...
- over 80% of defects are management
controlled, not operator controlled
- the scope of the number of places where
an operator could cause an error made the remedies more complex than
just motivations.
*Quality Planning & Analysis, 2nd
edition, Copyright 1980, Juran/Gryan pg. 138
