You get a message from your supplier saying that twelve thousand units that you ordered are finished. The vessel leaves in three days. Just to make sure everything is in order, you get a quality control inspection. Your inspector opens the first carton outside Ningbo, and the logo on the retail box is the wrong shade of blue. Not on one pallet. On all 12,000 boxes, because the printer ran the whole job in one pass four weeks ago. Your options are to accept the goods, pay for reprinting and miss the sailing, or cancel and miss the season. What you cannot do is go back to the morning the print run started, the day one inspector could have stopped it for the price of a single man-day. That gap, between finding a problem while it is fixable and finding it when it is packed, is the argument for during-production inspection.
What are the stages of inspection, and where do DUPRO and PSI sit?
There are five checks in a normal China order, at five different moments. Most importers only ever buy the fourth one, which is why they only ever find problems at the end.
- Factory audit, before you place the order. It looks at the company, not your goods: legal status, equipment, capacity, quality system. A separate report from the quality checks run during an order.
- Initial production check, at the first 10-20 percent: incoming raw materials, components, first pieces off the line, and whether the factory is using what you specified or a substitute.
- During-production inspection (DUPRO), at roughly 20-60 percent. Finished units exist, the line is still running, so changes are still cheap.
- Pre-shipment inspection (PSI), once at least 80 percent is produced and export-packed. The last look before the goods leave.
- Container loading supervision, on loading day: quantity, carton condition, stuffing, container quality. Worth ordering a loading inspection when the risk is short shipment or transit damage.
An audit is not an inspection. How a supplier really operates is a factory visit question, and it is done before you place the order.
What is a during-production inspection?
A during-production inspection is a check carried out while your order is still being made, normally when 20-60 percent of the units are finished. The inspector samples completed pieces and also watches the line: which materials are being fed in, how workers are assembling, what the factory’s own QC is rejecting, and how much is genuinely finished.
A DUPRO report describes a process rather than a batch. If a moulding machine is out of tolerance, the wrong screw is going into an assembly, or the print colour is off, you learn it with 40-80 percent of the run still to make. You also get an honest read on the delivery date.
What is a pre-shipment inspection?
A pre-shipment inspection is a random sample check of the finished, packed order, done once at least 80 percent is produced and export-packed. The inspector verifies quantity, opens cartons at random, compares workmanship to the approved sample, measures critical dimensions, runs agreed function tests, scans barcodes, checks labels and carton markings, and drop-tests a packed carton.
PSI is the workhorse of import quality control and you should book one on almost every order. It proves the goods exist, in the right quantity and packaging, before you release money. It cannot change how they were made.
A pre-shipment inspection tells you the truth. A during-production inspection gives you time to do something about it.
What can a DUPRO catch that a pre-shipment inspection cannot?
A DUPRO catches systematic defects while the line can still be corrected, and that is the only difference that matters. Both inspections find the same faults, at very different prices.
A wrong component spotted at 30 percent of production means the factory swaps the part and remakes a few hundred units. The same component at PSI means 12,000 units to open, strip and rebuild, or a rejected shipment. Identical defect, different bill. A PSI failure also lands when your booking is confirmed and the cut-off is this week, so your only choices are accept, rework or miss the season.
A DUPRO cannot do everything. Packing has usually not started, so it cannot check final packaging or verify full quantity, and it cannot confirm the last 40 percent was made like the first. It does not replace a PSI, it sits in front of one.
When is a during-production inspection worth paying for?
Buy a DUPRO when the cost of finding a problem late is far higher than one extra inspection day. In practice:
- New supplier, or one you have never seen produce this category.
- New product, or an existing one with a changed specification.
- First run off new tooling, where a mould fault repeats on every unit.
- Long runs, where machine drift affects thousands of pieces before anyone notices.
- A hard seasonal deadline: Christmas goods, back-to-school, a promotion date.
- Complex assembly with many components and sub-suppliers.
- Custom colours or printing, the classic irreversible defect. If you are working to Pantone or another colour system, get eyes on the first batch.
When is a pre-shipment inspection alone enough?
PSI on its own is enough when you repeat a known order with a supplier who has a clean record: same factory, same SKU, same materials, same packaging, several shipments delivered without a claim, and an order value small enough that a rejected batch would not hurt you. Be honest about “stable history”. Three good shipments is a history; one is luck. A repeat SKU with a new carton, label, colourway or sub-supplier is a new product wearing an old item number.
How does AQL sampling actually work?
AQL sampling under ISO 2859-1 sets how many units the inspector pulls and how many defects are allowed before the lot is rejected. You choose an inspection level, usually General Inspection Level II, and the lot size gives a sample size code letter. The letter gives the sample size and, for each AQL value, an accept and a reject number.
A lot of 12,000 units at Level II gives code letter L: a sample of 200 pieces. At the common setting of zero critical, AQL 2.5 major and AQL 4.0 minor, the inspector may accept up to 10 majors and 14 minors. The eleventh major fails the lot. The AQL table does the arithmetic, and the AQL standard is worth understanding before you sign a contract referencing it.
Now look again: 200 pieces out of 12,000 is 1.7 percent of the shipment. A PSI report says “pass” on a sample, not on the container. Sampling bets that a batch with few defects in the sample has few overall. It is the only affordable way to inspect, but it works badly against defects that are rare or hidden inside the product. A DUPRO improves the odds by checking the process behind every unit.
How do you book an inspection and what goes in the brief?
You book directly with a third-party inspection company, usually about a week ahead, after confirming that production will really be at the required stage. Inspection in China is priced per man-day: one inspector on site for roughly eight hours. Mainstream providers mostly publish rates of about USD 200 to USD 350 per man-day, with budget operators below USD 200 and factory audits higher. Remote factories add travel charges, and a wasted trip is billed in full.
The buyer pays. If the supplier offers to arrange and pay for it, decline: an inspection the factory commissions is not independent. Write your right to inspect, and the consequence of a failure, into the purchase order.
A good brief contains:
- The approved golden sample, at the factory or with the inspector.
- A written product specification sheet with dimensions, materials, weights and tolerances.
- Colour references, packaging and label artwork, carton markings.
- Barcode numbers and the destination market rules the labels must meet.
- The inspection level and AQL values to apply.
- Your definition of critical, major and minor defects for this product.
- The on-site tests you want run: function, power-on, zipper cycles, fit, drop test.
What should the report include, and when do you pay the balance?
A usable report includes photographs of every defect, quantity verification, defects classified as critical, major and minor against the AQL limits, measurements against your tolerances, on-site test results, barcode scans, label and marking checks, carton dimensions and weights, and a drop test result. Photos are the part suppliers argue with least.
Then the mistake that undoes all of it: releasing the balance payment before the report arrives. Once the 70 percent is paid, you have nothing left to bargain with, and a failed report becomes a negotiation you cannot win. The sequence is inspection, report, your decision, payment, release of goods. Put it in the purchase order that way and hold to it.
If you are building a process rather than booking a one-off check, start with how quality control in China works across a whole order, and consider a factory inspection in China before you commit to a supplier. Both cost less than a container of unsellable stock.
Frequently asked questions about product inspections in China
What is a during-production inspection?
A during-production inspection is a quality check carried out while your order is still being manufactured, usually when 20-60 percent of the units are finished. The inspector samples completed pieces, reviews the materials and components in use, watches the assembly process and verifies the real production schedule. Its purpose is to catch systematic defects while the line can still be corrected.
What is the difference between DUPRO and pre-shipment inspection?
The difference is timing, and timing decides what you can do about a problem. A DUPRO happens at 20-60 percent of production, so a fault found is a fault the factory can still fix on the remaining units. A pre-shipment inspection happens at 80-100 percent produced and packed, so a fault found leaves you three choices: accept, rework, or miss the shipment.
At what stage of production should an inspection happen?
There are four stages during an order: initial production check at roughly 10-20 percent on incoming materials and first pieces, during-production inspection at 20-60 percent, pre-shipment inspection once at least 80 percent is produced and export-packed, and container loading supervision on loading day. A factory audit is separate and belongs before the order is placed.
How much does a product inspection in China cost?
Inspections in China are priced per man-day, meaning one inspector on site for about eight hours. Mainstream providers mostly publish rates between roughly USD 200 and USD 350 per man-day, with budget operators below USD 200 and factory or social compliance audits higher. Remote locations add travel charges, and large orders may need more than one man-day.
Can you inspect goods after they have already shipped?
You can inspect goods after shipment, but only at your own warehouse or a bonded facility in the destination country, and by then you have paid the supplier, the freight, and the duty. Rejecting goods at that stage means a claim against a supplier who already holds your money. Inspection is worth far more before the container is sealed.