With all due respect, you cannot "inspect quality" into your product. By the time inspection gets to it, either the product is in spec or it isn't. No amount of measuring or weighing will change that. If the NDI inspector find a crack, the inspection will not un-crack the part.
Also with all due respect, the above sentiment is absolutely incorrect. Inspection is most frequently a means to prevent defects from reaching the customer. It can’t fix the individual defect, but it CAN AND DOES fix your saleable product volume.
As I pointed out above - inspection is not a lead measure for quality CONTROL, but rather is a lag measure for quality ASSURANCE. In a manner of speaking, inspection can absolutely reduce the number of defects which reach the market.
Improving QC methods is not the only role of QA. If a manufacturer produces and inspects 10,000 triggers, and they catch every defect with insufficient sear length or chipped edges, they’ll send out a perfect batch. If their QC is bad, they’ll only have 1,000 left to sell instead of 10,000, so that’s their “Cost of Poor Quality.”
Quality Assuance is used in all kinds of industries to improve saleable product quality (or even reduce it to industry standards). The good ol’ RBOB is an example of how QA inspectjon is used to REDUCE product quality - reformulated gasoline produced which has a lower RVP than required by the destination state is then blended with high range RVP or even out of high spec batches to hit the states’ mandates. In other words - great gas is tainted with poor gas to make OK gas. Another example of a QA program effect on saleable product quality is the food industry - metal detection at the front of food production processes - quality control - is only refined enough to stop large enough pieces of metal which would damage equipment. The product metal detection limits are set to reject MUCH smaller particles. For some food production processes - example: whole muscle meats like steak - there is no metal detection up front, only on the output product. So in a world where a piece of slag in your Sirloin is a defect, the ONLY quality control mechanism is actually a quality ASSURANCE inspection of the finished product, before it leaves to be sold to the consumer. Pharmaceutical products work much the same way, input products are certified by their respective manufacturers, but are not quality tested by the final drug manufacturer - so the QA program by the primary site acts as part of the QC program for the final product manufacturer. The final producer then inspects, analyzes, and certifies his finished product for quality, and rejects out-of-spec product.
CCI’s BR primers are another example - they check weigh every individual primer in a batch to ensure tight tolerances. Out-of-spec primers are rejected from the batch, which assures product quality to the customer, who is wanting a consistent lot of primers. So this inspection process indeed reduces the variability of the product the consumer will buy - in a world where out of tolerance variability is a defect.
Ford sells trucks - if their brake rotor inspection process eliminates all excursions of trucks hitting the lot with cracked rotors, then inspection DID improve quality of their products. Colt sells AR’s, if MPI’s - magnetic particle INSPECTIONS - eliminate their AR’s from hitting the sale rack with cracked bolt lugs, then their product quality is improved by inspection. Without question, Ford would still have a pile of rejected cracked rotors, and Colt would still have a pile of rejected, cracked bolts, but neither hit the consumer.
