During-production inspection (DUPRO) explained

A pre-shipment inspection tells you whether to release the balance. It does not help you if the whole run is already wrong, because by then the goods are made and your only options are reject or rework. A during-production inspection, or DUPRO, checks the goods while the line is still moving, so you catch a systematic fault on unit fifty instead of unit five thousand.

What a DUPRO is

A DUPRO is an inspection carried out partway through manufacturing, while production is still in progress. An independent inspector visits the factory, pulls units from what has already been made, and checks them against your specification: dimensions, materials, workmanship, function and early packaging.

The point is timing. The goods are far enough along to show real quality, but not so far that a problem has been repeated across the entire order.

When to schedule it

The widely used guideline is to inspect when roughly 20 to 80 percent of the order is complete. That window is wide on purpose, and the right point depends on the order:

• Book it early, near the 20 percent mark, when you are most worried about the raw materials or components going into the product.
• Book it later, closer to 70 percent, when your bigger concern is the finished workmanship and assembly.
• For a long run, two DUPROs can make sense: one early to verify inputs, one later to confirm the finished quality is holding.

The single worst time to find out about a material problem is after every unit has been built with it.

What a DUPRO catches that a final check misses

The cheapest mistake to fix is the one the factory has only made fifty times, not five thousand.

A final inspection is a verdict. A DUPRO is an early warning. It is built to catch:

• Wrong materials or components going in before the whole order uses them.
• A misread specification that has the line building the wrong thing.
• Process faults such as weak seams, poor welds or bad moulding that repeat on every unit.
• Drift, where the first units were fine but quality is slipping as the run continues.

Caught here, these are a quick correction and a conversation. Caught at the end, they are a rejected order and a delayed shipment.

How a DUPRO fits your QC plan

Think of inspections as a sequence, not a single event:

1. Approve a golden sample so the factory and the inspector share one reference.
2. Run a DUPRO partway through to confirm the line is building to that reference.
3. Run a pre-shipment inspection once the goods are finished and packed, before the balance is paid.

For a large or high-value order, or for a first run with a new supplier, the DUPRO in the middle is the step that stops a small mistake from becoming the whole shipment.

Brief it like any inspection

A DUPRO is only as good as the brief. Give the inspector your spec sheet, your approved sample photos and the defect classes you care about, and tell the supplier in advance. A reputable factory treats a mid-run inspection as normal; resistance to it is its own warning sign, the kind we discuss in vetting a 1688 supplier.

Build the DUPRO into your timeline before the deposit goes out, so the supplier expects it. When the deposit is due you can make a request to settle it in RMB on Alipay from Naira, with the mid-run check already booked to keep the run honest.