Re: Cost vs. Quality Graph

[Myron Tribus <mtribus@earthlink.net>]

The concept of "Cost of Quality" was coined by Juran.  Heauthored the 
Quality Control Handbook (McGraw Hill,  1951, 1979, 1962)  I have the 
Third Edition.  Section 5 is devoted to Cost of Quality.  and extends 
for 22 pages.  On page 5-13 he shows a curve which is concave 
upwards.  He proposes a minimum cost at a tradeoff between a "zone of 
improvement" and a "zone of perfectionism".  All of this was written 
before Dr.Deming came to prominence and before the Japanese 
experience proved it WRONG!

Quite a few years later (I have lost the reference) Dr. Juran 
attempted to recall all of this.  He explained that he had not 
factored into the presentation the effect of continual improvement in 
process and design.

Today, people who understand how continuous improvement works know 
that cost and quality are not components of a "tradeoff" .  They are 
related in this way:

If you try to cut costs,  you will decrease quality.
If you try to increase quality, you will cut costs.

But, in all this you must not confuse quality with features as the 
people in the housing industry often do.  A home may be advertised as 
"high quality" because it boasts complete air conditioning, with 
climate control, has special windows, modern kitchen, multi-baths, 
etc., etc.   However, the roof may leak, the ground may subside, 
rain may cause flooding, etc., etc.

Features  include the various characteristics you add to a product to 
attract certain customers.  Features usually cost money and increase 
cost.  Whether or not they are worth the cost depends on the 
customer's needs and circumstances.

quality  describes the integrity with which the features are 
delivered.  Quality is determined by the processes used to produce 
the product and, as such, is under the control of the management 
which establishes the conditions of work.

Myron Tribus,   Web Master www.icelp.org
350 Britto Terrace,   Fremont,  CA  94539
Ph:510 651 3641  FX: 510 656 9875
mtribus@earthlink.net
"Experience is a great teacher.  Unfortunately there are few students."