A pre-shipment inspection is the last point where a problem is the factory’s to fix cheaply, not yours to fix expensively after the container’s already on the water.
AQL sampling, not 100% inspection
Pre-shipment inspections almost never check every unit, they use an Acceptable Quality Limit (AQL) sampling plan that pulls a statistically representative sample based on order size. A small number of defects within the sample is normal and expected, the sampling plan tells you the threshold where the full order gets flagged, not whether any single defect exists.
This is the cheapest point to catch a problem
Once cargo is on the water, fixing a quantity shortage or a spec mismatch means air freighting replacements, which usually costs more than the original shipment. A PSI costs a few hundred dollars and happens while the factory can still fix things on-site. Skipping it to save that cost is rarely worth it on anything beyond a trusted, repeat supplier relationship.
Once inspection passes, move to the container loading checklist for how the goods get packed for transit.