Buyers often ask us, how to do quality inspections in “stricter” way with some of their suppliers in China or Vietnam.
1) An easy way is to set reduce AQL limits, but the supplier might refuse.
I know of a large company that sets the AQL limit at 0.65% for major defects. In the garment industry. Most people (especially suppliers) say it’s unheard of. And of course most garment factories refuse to work with those large companies. But it is possible if your volumes are high and you can accept a slightly higher price.
2) Another approach is to define what a major defect, a minor defect, and a “no defect” are in a stricter manner. The supplier is less likely to refuse this outright. However, once they see the consequences (many defects classified more severely than they think is appropriate), expect some pushback.
3) You could follow inspection level III, or maybe something even higher (if you have access to Minitab you can adjust the limiting quality as suggested here).
4) You could do a random inspection first, and find some defects. Then, in a second step, you could do a 100% check (on the whole batch) that only focuses on the 1 or 2 most frequent defects found in the random inspection. (If you do a 100% check for all defects, it takes much longer.)
5) If you are a relatively large customer, you could request the manufacturer to work with a consulting company. This way, they will put in place the process controls they need, as well as a proper quality system.
These are the main options that come to my mind.
And remember, if you are not happy with your supplier, you should pick another one. I know it sounds very condescending, but one can’t turn a donkey into a racehorse…