Most buyers learn inspection the hard way. The first shipment arrives, the cartons look fine, then you open a box and find the logo printed 4mm off-centre, the zipper on the wrong side, or a plug that will never pass your local safety rules. The factory says the goods match the sample. You say they don't. Nobody has photos from production day, and the balance payment is already gone.
Inspection exists to move that argument earlier, to a point where the goods are still in China, still not loaded into a container, and still fixable.
What inspection can and cannot do
An inspection is a measurement, not a repair. It tells you what the lot looks like on the day the inspector walks in. It cannot make a weak supplier good, and it cannot catch a defect the whole factory considers normal. What it does well is catch the gap between the approved sample and the mass production run: wrong material, thinner gauge, sloppy stitching, missing accessories, wrong label, wrong plug, wrong carton marking.
Used properly, a pre-shipment inspection usually costs less than 1% of order value. That is cheap compared with air-freighting replacements or writing off a season of stock.
The four inspection points in a production cycle
| Stage | When | What it answers |
|---|---|---|
| Pre-production inspection (PPI) | Before mass production starts | Are materials, components and the first-off sample correct? |
| During production (DUPRO) | 20–60% produced | Is the line making the right thing, or repeating a mistake 5,000 times? |
| Pre-shipment inspection (PSI) | 100% produced, 100% packed | Can I release the balance payment and book the vessel? |
| Container loading check (CLC) | During loading | Did the right quantity and the right cartons actually go in? |
For most small and mid-size buyers, PSI is the one that matters. If the order is complex, the product is new, or the factory is new to you, add DUPRO. It costs one extra man-day and often saves a full rework cycle.
How AQL actually works
Inspectors do not check every unit. They sample, using AQL (Acceptable Quality Limit) tables from ISO 2859-1 / ANSI Z1.4, General Inspection Level II by default. You and the supplier agree on defect classes and limits in advance. A common setup:
- Critical: 0 accepted (safety issues, banned substances, anything that could injure a user)
- Major: AQL 2.5 (defects that make the product unsellable or returnable)
- Minor: AQL 4.0 (cosmetic issues buyers notice but tolerate)
| Lot size | Sample size | Critical (0) | Major (2.5) | Minor (4.0) |
|---|---|---|---|---|
| 151–280 | 32 | 0 | 2 | 3 |
| 281–500 | 50 | 0 | 3 | 5 |
| 501–1,200 | 80 | 0 | 5 | 7 |
| 1,201–3,200 | 125 | 0 | 7 | 10 |
| 3,201–10,000 | 200 | 0 | 10 | 14 |
Read the numbers carefully. With 80 pieces sampled and AQL 2.5, three major defects fail the lot. That is not a tiny margin; it means a defect rate somewhere around 3.5% gets caught. If your customer base is unforgiving, tighten major to 1.5 and define critical defects broadly. Do not simply accept the inspector's default because it is the default.
What to send before the inspector arrives
The inspector is not a product specialist. They follow your instructions. If your checklist says 'good quality', the report will say 'good quality'. Send:
- A signed, sealed golden sample, kept at the factory or at your agent's office
- A written spec sheet with tolerances: dimensions, weight, material, and colour references such as Pantone codes
- Packaging artwork, dieline, barcode and label files, plus retail carton dimensions
- Carton marking and shipping mark instructions
- Any certification or test report the goods must carry (CE, RoHS, FCC, LFGB, CPSIA, UN38.3 for batteries)
- Function tests you want performed, and how many units to test
- On-site tests allowed: drop test, pull test, colourfastness, salt spray, cycle testing
Two pages of specific instructions beat ten pages of generalities. If you do not know what to write, ask someone who has inspected this product category before. The defect list for knitwear looks nothing like the one for LED panels.
Where inspections go wrong
- Booked too late. The goods must be finished and packed. Inspectors cannot sample what is still on the line, and factories happily promise 'almost done' for a week.
- No golden sample. Without a signed reference, every defect becomes a debate.
- Inspection on the day of loading. If the container is already sealed, you have lost your chance to act.
- Wrong address. Trading companies sometimes send inspectors to a showroom rather than the actual production site.
- Report read as a pass/fail grade only. The measurement tables and photos are where the real information sits.
Reading the report without being an expert
Ignore the headline. Open the measurement data. If the spec is 30cm ±0.5cm and the readings cluster at 29.3cm, you have a systemic problem, not a random one. Look for photos with a ruler or caliper in frame. Compare carton weights against the packing list; a 400g shortfall per carton across 2,000 cartons means a supplier who quietly changed material.
Red flags worth a phone call: no photos of packed cartons, 'not applicable' against every on-site test, handwritten corrections, a report that arrives before the inspector's flight lands, or an inspector who took the factory's shuttle back into the city.
When the inspection fails
You have four realistic options, roughly in order of preference:
- Rework and re-inspect. Cheapest if the factory is capable and the ship date allows.
- 100% sorting. The factory or a third-party sorting team checks every unit and ships only the good ones. Decide who pays before production starts, not after.
- Price adjustment. Accept the lot with a credit that covers your own rework or the discount your customer will demand.
- Delay or cancel. A last resort, and the reason payment terms in your PO matter as much as the inspection itself.
Whatever you choose, put it in writing the same day. Verbal agreements with factories dissolve quickly once the vessel sails.
Audits and inspections answer different questions
An audit asks whether the factory can make your product: equipment, QC process, staffing, certifications, sub-contracting. An inspection asks whether they did. An audit before the first order plus a PSI before every shipment catches most problems. If you only have budget for one, choose the inspection.
What it costs and how far ahead to book
| Service | Typical cost in China | Lead time |
|---|---|---|
| Pre-shipment inspection | USD 250–350 per man-day | Book 3–5 working days ahead |
| During-production inspection | Same | Book at 30–50% production |
| Factory audit | USD 400–800 | Book 1–2 weeks ahead |
| Container loading check | USD 150–250 | Same day as loading |
Remote provinces such as inland Sichuan, Yunnan or parts of Hebei add travel cost and a day of scheduling. Reports should land in your inbox within 24–48 hours; insist on that in writing before booking.
A short checklist before you release the balance
- Golden sample signed and dated by both sides
- Spec sheet and packaging files sent to the inspector at least 48 hours ahead
- Inspection booked before the vessel cut-off, with a buffer
- Report received with measurement data and photos, not just a summary
- Defect counts compared with the AQL agreed in the PO
- Any failure discussed with the factory in writing before payment
- Loading photos or a CLC if the order is large enough to justify it
None of this requires you to speak Chinese or fly to Guangdong. It requires someone on the ground who knows the difference between a factory and a trading company, and who will tell you plainly that a report with 11 major defects is not a minor issue.
Globesino handles factory sourcing, audits, pre-shipment inspections and shipping from China on your behalf, with English-language reports you can act on. Send us your product spec and we will map the right inspection points for your order.