Inspection guide
PSI vs DPI: choose by correction window
Practical buyer guide.
DPI and PSI solve different timing problems. A during-production inspection is most valuable while the supplier can still correct repeated defects, quantity gaps or process drift. A pre-shipment inspection is most valuable when finished goods can be evaluated before final release.
Use DPI when correction time still exists
If meaningful production is underway but not complete, inspecting now can identify systemic issues before they affect the entire lot.
Use PSI when the final product is ready
PSI focuses on finished goods, quantity, specifications, function, packaging and agreed checkpoints before shipment.
Sometimes the correct answer is both
A high-risk order may justify DPI now and PSI later. The first controls production risk; the second verifies the final result.
The inspection scope and sampling basis must be agreed for the specific product and buyer requirements.