Haw could I reduce the cost of the non quality. Is it reliable to speak about Zero defect in an industrial context?

I agree with the answer.

Mr. Ahamed Shareef

Problem solving process steps:

1. Identify and Categorize areas where you are losing money for quality reasons - External failures, Internal rejections

2. Use pareto analysis to identify vital few contributing80% of the defects.

3. Initiate a continuous improvement projects for the key defects reduction - Independent projects by different team for each defect type would be a better option. Create these cross functional teams involving the employees who work on them.

4. Use Basic7QC tools for the operational defects which can be resolved by shopfloor teams. If defect is technical in nature and needs an experts to resolve, use experts in the area to lead these projects. (These projects can be six sigma projects)

5. Where required, use DOE to identify major root causes and to test solutions. DOE helps in optimizing the process parameters for best results.

6. Once solutions are generated, establish process controls to sustain the benefits. Create a sustanance plan and implement.

The above process steps can help bring down COPQ.

Zero defect concept is hypothetical in nature. However, it is very familiar in Automotive industry and Aerospace industry. It introduces, several concepts including tough targets for Quality performance (but not really Zero defects!) and Zero acceptance criteria inspection plans, etc.

Taguchi's Loss Function (Zero defect)  model defines, product and processes to be designed to achieve mid target of a specification. Tolerance is not acceptable in this concept and shift from the mid target is considered as deviaton or loss for the customer. However, still it is not familiar in industrial circle and is in research state...

That depends on your quality assurance process. If quality assurance is integrated into your production processes your nonconformance cost will be much lower than if you assure quality at the end of processing.

Regarding0 defect, I know that the Japanese achieved that. It is said that a buyer purchased Japanese TV sets and based his acceptance on no more than2%. He received the shipment with exactly2% defect.

Zero defet can be achieved only on papers but on reality is something els, thus achieving the goal would not be economically feasible

Cost of poor quality can be reduced by making your QMS strong & following that systems honestly.

Regular analysis, find out the root cause by using QC tools, Six Sigma, SPC etc then improve the process & maintain/sustain.

Zero defect is not possible but what I understand is we have to continusly keep lower ppm targets (SMART Targets) & achieve them. 

I beleive errors and defects occur due to negligence of the individuals. Organisation loose a lot interms of quality ,cost etc. The lean concept help the organisation to overcome these problems. Toyota production system ,5S are some of the concepts which the organisation are using to have a better quality output. I beleive this can happen if the organisations implement these concepts in an effective manner. 

There are many organisations in the world that have shown the results Zero defect can be achieved but for this all employees and management have to establish the new concepts in their production line so as to achieve this.

There is no such thing as cost of quality.  There is only cost of poor quality, i.e. cost of rejection.  The most important thing is to manufacture quality, not inspect it.  To do this, you need to improve the process capability (Cpk) of each process.  If you can achieve a Cpk of1.33 on each process, your defect rate will be around0.26%, and if you can achieve a Cpk of1.67 or better, you will have negligible defects.