Buyers lose money on inspections in two ways: skipping them, or booking the wrong one at the wrong time. This article explains the three inspection types used in China manufacturing, what each actually catches, and how to choose based on your order.
Quick Comparison
| Pre-Production (PPI) | During-Production (DUPRO) | Pre-Shipment (PSI) | |
|---|---|---|---|
| When | Before mass production starts | 20–40% complete | 100% produced, ≥80% packed |
| Catches | Wrong materials, wrong components | Systematic defects early | Everything remaining — final gate |
| Cost to fix findings | Lowest | Low-medium | Highest |
| Cost | 1 man-day (~$268–350) | 1 man-day | 1 man-day |
| Best for | Custom/OEM, new suppliers | New products, larger orders | All orders |
Pre-Production Inspection (PPI)
The inspector visits before mass production begins and checks:
- Incoming materials and components against your spec sheet — fabric rolls, plastic resins, electronic components, hardware
- Whether materials match the golden sample and approved samples
- Production readiness: is the factory actually planning to make your goods on-site, or subcontracting?
- Equipment and production plan
What it catches that nothing else can: material substitution at the source. If the factory bought 201-grade stainless instead of 304, or a cheaper fabric lot, you find out before a single unit is made — when replacement is a purchase order, not a crisis.
When you need it: custom/OEM products, first order with a factory, any product where raw material grade drives cost (metals, fabrics, cosmetics ingredients, candles wax blends).
Honest note: for simple, off-the-shelf products from an experienced supplier, a PPI is often overkill. Put the budget into a PSI.
During-Production Inspection (DUPRO)
Booked when roughly 20–40% of the order is finished. The inspector checks:
- Semi-finished and finished goods against spec
- Whether defects are random or systematic — the single most valuable data point
- Production status and estimated completion (catches delays before they eat your shipping window)
- Whether the factory has started packing, and packaging materials match spec
The key insight: at 30% completion, systematic defects can be corrected across the remaining 70% at factory cost. The same defect found at PSI means negotiating rework of 100% of goods — with a factory that has already spent its budget and your deadline approaching.
When you need it: new products (first or second production run), larger orders ($15,000+), tight delivery windows where discovering a delay late is fatal, and any supplier with a history of "sample great, bulk not so much."
Pre-Shipment Inspection (PSI)
The final gate, when 100% of goods are produced and at least 80% packed (inspection of unpacked goods is meaningless — packing quality is part of quality).
A standard PSI covers:
- Quantity verification against PO
- Random sampling per AQL — see AQL sampling explained for how sample sizes and pass/fail limits work
- Workmanship and cosmetic checks against your defect classification
- Function and safety tests specific to the product
- Packaging and shipping marks: carton quality, inner packing, labeling, barcode scan tests, carton drop test (a standard ISTA-style drop test costs nothing extra and catches the #1 cause of damaged goods)
- Container loading supervision (optional add-on): inspector watches the loading, verifies container condition, seals the container, photographs the seal
Why "after inspection" must be tied to final payment: a PSI report is leverage. If you've already paid 100%, the report is a postcard. Structure payment as balance-due-after-passed-PSI whenever the supplier relationship allows — this is the single most valuable sentence in this article.
Which Inspection Does Your Order Need?
Simple product, experienced supplier, $2–8k order: PSI only.
New product development, first production run: PPI + DUPRO + PSI (the full chain — roughly $900–1,000 total on a typical order; compare against your defect cost).
Repeat order, clean history: PSI, possibly every second order.
Big order, tight deadline (e.g., pre-Christmas): DUPRO + PSI, plus container loading supervision.
Supplier you're nervous about: unannounced PSI (booked 1–2 days out, so the factory can't prepare a "golden corner" of perfect cartons for inspection).
FAQ
Can one inspection cover multiple types? If DUPRO findings are clean and production finishes quickly, some buyers convert to a final random inspection. But formally, each is a separate service/man-day.
How long does booking take? Standard third-party firms need 2–5 working days' notice. Rush bookings (48h) are often possible in major industrial cities.
Do I need to be in China? No. You receive a 40–60 page photo report same day. The inspector never represents your interests emotionally, though — that's what your spec sheet is for.
Who books the inspector — me or my agent? Either. What matters is independence: the inspector should not be paid by the factory. See third-party inspection costs for pricing structure and red flags in inspector selection.
给编辑的备注
- 配图建议：三种验货的场景对比图（可用信息图：时间轴形式）
- 结构建议：文首对比表是本页核心，可做成 Pinterest 适合的竖版信息图引流
- 内链替换：方括号链接替换为集群内对应文章 URL
- 回链：结尾 CTA "Not sure which inspection your order needs? Get a free assessment"