I am new to this concept bit I have read some books on this.
One thing really confuses me is one statement - "errors detectable by customer". ( 4 / million)Is this true)?
If it is there are many products where the customer will not know the difference or will notice after years. For example, Soft drinks are being projected as health hazards after years and tons of consumption. Will this constitute failure?
One more thing (I read a question on implementation of Six sigma in Microbiology and one on hand made products). Machines and human beings are different. I wonder if a human being can ever guarantee to breathe same way even 100 times ( I know I am stretching it too far).
Anyway, my main question is - is it to be targetted to detectable by the customer or in real?
Regards,
Dr Hemant