How can we ship zero defectives? Zero Defects Sampling?



One of our customers says we have to establish the " production and quality system to provide a product with zero defects" .We are trying our best to provide zero defect products but has anyone achieved this target. What should be done to ensure zero defect products.

Zero defect sampling does not help as far as I am concerned. What do the forum users feel?

Even if we make the process deliver zero defects, how can we prove it?

M Greenaway

If you ever make a process that delivers zero defects you have created a unique process in the history of mankind - well done.

Mike S.

Happy to be Alive
Trusted Information Resource
Looks like we found something we can (mostly) agree on, Martin!

IMHO most industrial mfg. or service processes cannot in the real world, over a long period of time, produce zero defects. Maybe, just maybe, if the tolerances of the customer were super-wide open and the product super simple, but how many times does that happen?

A "production and quality system to provide a product with zero defects"? I'd ask the customer how they have decided to achieve that -- ask them and their "wisdom" to educate you.


M Greenaway


Over-engineering does take place, but normally not to such an extent as never supplying defects due to tolerances being hugely wide in comparison to process capability.

Most companies would be happy with a process that performs within +/- 3 standard deviations. Leading companies who supply critical products to very stringent customers (such as automotive) would be happy perhaps with +/- 6 standard deviations, and would probably be considered 'World Class'.

Douglas E. Purdy

Quite Involved in Discussions
Any Phil Crosby enthusiasts out there, or Graduates of his Quality College? I think you realists have distorted the customer's intent. Hopefully you can make defect free product! Now as to some product having a defect, you may be able to talk about the level of quality (e.g., Parts Per Million) but your quality management system should be able to provide defect free product to the customer! Or am I missing something here?

M Greenaway

Sorry I think you are missing something.

I am more of a Deming enthusiast, i.e. avoid exhortations in the work place, and dont set unachievable targets !

Douglas E. Purdy

Quite Involved in Discussions
I don't know, I like all the Quality Gurus (Deming, Juran, and even Crosby) they have good principles to build a Quality Management System. But saying that you can not create a system where you are competent that only so many defects would be present, is someone I would not likely choose as a supplier.

As a "Shy Browser" this will be it from me!

M Greenaway


Admittedly I do not know the full content of Crosby's Zero Defects system, however by the title I have always imagined that it meant producing totally defect free product - I dont believe that can be done. As for having a consistent output of 'nearly' defect free then yes that can be done, and is our never ending goal to improve on.

But is zero defects achievable ?

Have you witnessed this ??


Given the recent developments in quality as a partnership and continual improvement, the concept of zero defects might be given a different look. If you consider the definitions of defect and nonconformity it could possibly be applied.

Defect: - a departure of a quality characteristic from its intended level or state that occurs with a severity sufficient to cause an associated product or service to not satisfy intended, normal or reasonable foreseeable usage requirements. (Armand V. Feigenbaum – Total Quality Control 3rd Edition Revised)

Nonconformity: - a departure of a quality characteristic from its intended level or state that occurs with a severity sufficient to cause an associated product or service to not meet a specification requirement. (Armand V. Feigenbaum – Total Quality Control 3rd Edition Revised)

The concept of “Zero Defects” now becomes a commitment to not supply any product which would cause an associated product not to satisfy intended, normal or reasonable foreseeable usage requirements. This is certainly achievable within the statistical boundaries set by a stable process. A nonconformance to this commitment can be classed as a “Gross Nonconformance”.

Now quality becomes a true partnership. Assuming a capable and stable process, the supplier has committed to not supplying a “Gross Nonconformance” while continuing to improve the process by reducing minor nonconformance. The customer, now confident of “Zero Defects”, accepts and uses product supplied under a normal capable and stable process knowing any minor nonconformance which may statistically be present will not be detrimental to his product.

Obviously, in addition to the supplier/customer partnership, the definition of “Gross Nonconformance” is critical to satisfactory implementation of this “Zero Defects” concept. It could be stated that any nonconformance undetectable to the customer through subsequent testing or use could be called “minor”. Anything the customer could detect would then be classed “Gross”. This may not, in all circumstances, consider the “usage” requirement identified earlier.

The preferred method would be to define “Gross” at the APQP stage. Each part controlled and monitored with its own criteria. Minor nonconformance would be brought to the attention of the customer and a mutual agreement to “usability” would be made.

Given the right elements of partnership, planning, communication and process stability, it would seem possible to reach a plateau of “Zero Defects”.

Just my opinion but it is what I am preaching to our company.


Dean P.

Maybe I'm looking at this too simplistically (is that a word?)

The customer has requested that you provide them with a product with zero defects. I read this to mean that the customer does not want to see any defects from you. This doesn't mean that you cannot produce defective product, it just means that you must catch it before it reaches their dock.

Does this make sense?? A production manager's goal is always to produce zero defects, but the ultimate goal of a company is to supply product with zero defects. Two different scenarios, although achieving the first part will make the second automatic.

Just a thought.
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