I worked for a manufacturing firm years ago and a director once told me 30 was the magic number. Order 30 units and the error rate will scale from there if for

I worked for a manufacturing firm years ago and a director once told me 30 was the magic number. Order 30 units and the error rate will scale from there if for example you get 3 in 30 broken you'll have about 10% broken no matter how many you order.