The final random inspection (also called “pre-shipment inspection”) is by far the most common type of QC check. It takes place once 100% of shipment quantity is finished and at least 80% is packed, so it can be a real random inspection (this is not exactly the case if quality is checked earlier earlier) and suppliers cannot play games.
It puts pressure on suppliers and gives power to buyers. Its objective is really to confirm a shipment’s quality, rather than catching issues early. Therefore I usually advise my clients to complement final inspections with a DUPRO, to avoid finding disasters at the last minute.