99.8% has been the required quality target for our biggest customer for years. Below that, you get lots of “help” from the customer and less new business. It is darn hard to meet, and it has taken lots of different tools for us to get there.
Part of the answer is forming good relationships with the customer’s QE’s that I have to deal with. With targets like this, every little bit helps, and if you are able to form a good relationship and are proven to be an honest and trustworthy person, sometimes you get the benefit of the doubt when the cause is in that grey area between “their fault” or “our fault” or “purge stock” or “no need”.
Also, just like your sampling plan, the customer will usually not detect every nonconforming part. If it is something minor like the flange on a part is .003” OOT but it still fits when the mechanic grabs the part to bolt it on, no one knows. Does that mean you can or should “slip in” those bad parts and try to sneek them past your customer? No! But in reality, no matter what way you measure quality, you are not likely catching every defect, and neither are the customers. What you measure is best-case.
And of course it takes good old fashioned, best-effort based on what you can afford to do and still stay in business, QA and QC practices. Take PA and CA seriously. Hire good people. Treat them well. Walk the talk.
Part of the answer is forming good relationships with the customer’s QE’s that I have to deal with. With targets like this, every little bit helps, and if you are able to form a good relationship and are proven to be an honest and trustworthy person, sometimes you get the benefit of the doubt when the cause is in that grey area between “their fault” or “our fault” or “purge stock” or “no need”.
Also, just like your sampling plan, the customer will usually not detect every nonconforming part. If it is something minor like the flange on a part is .003” OOT but it still fits when the mechanic grabs the part to bolt it on, no one knows. Does that mean you can or should “slip in” those bad parts and try to sneek them past your customer? No! But in reality, no matter what way you measure quality, you are not likely catching every defect, and neither are the customers. What you measure is best-case.
And of course it takes good old fashioned, best-effort based on what you can afford to do and still stay in business, QA and QC practices. Take PA and CA seriously. Hire good people. Treat them well. Walk the talk.

