Why Wait Until the Order Is Finished?

The standard quality plan for an overseas order is a pre-shipment inspection: the goods are packed in the factory warehouse and an inspector pulls a sample. If it fails, you have a full order of defective product, a factory that wants payment, a vessel booking you will miss, and two bad options. Rework everything, which takes weeks nobody budgeted, or accept the shipment and eat the returns.

A during-production inspection, universally called DUPRO, moves that discovery point earlier. An inspector visits while the line is running, checks parts coming off it, and reports the same day. A problem found at 20 percent completion affects a few hundred units. The same problem found at the end affects all of them.

When to Schedule It

The standard trigger is when 10 to 30 percent of the order is complete and at least some finished units are packed. That window matters. Too early and there is nothing representative to look at, because the line is still being set up and operators are still learning the assembly. Too late and the corrective value drops toward zero.

For a long order, more than one DUPRO is reasonable: one at 15 percent and one at 60 percent. For a first order with a new supplier, always schedule one regardless of order size. For a repeat order of a stable product with a factory you have used successfully, DUPRO can sometimes be dropped in favor of a pre-shipment check alone.

Inspection firms need five to seven days of notice, and the factory has to tell you honestly when it will hit the completion threshold. Factories routinely report being further along than they are, so ask for photographs of the running line before committing an inspector to a date. A wasted trip is billed.

What the Inspector Actually Checks

A DUPRO is broader than a sampling check on finished goods, because the line itself is available to examine. A competent inspection covers:

  • Progress verification. How many units are actually complete, how many are in work in process, and whether the schedule the factory reports matches the floor. This alone often justifies the trip.
  • Raw material and component verification. Are the resin grade, the fastener spec, the motor, and the battery cells the ones on the approved BOM, or has something been substituted? Check labels on the actual cartons in the material store.
  • Semi-finished parts. Molded parts, painted parts, and sub-assemblies before they disappear inside a housing. Once a device is closed and packed, an internal defect is invisible without destructive teardown.
  • Finished units against the golden sample. Color, texture, fit, print position, and function compared side by side with the reference unit that both parties signed off, which is the entire reason to establish a golden sample before production.
  • Dimensional checks. Critical dimensions from your drawing, measured with calipers or gauges, on parts from the current run rather than on retained samples.
  • Function and safety tests. Power-on, run cycle, charge, drop, high-voltage or ground-continuity checks as specified in your test plan.
  • The factory's own QC records. Does the line have in-process check sheets, are they being filled in in real time, and what defect rate do they show? A blank or retroactively completed sheet is itself a finding.
  • Packaging and labeling. Retail box artwork, barcodes, country-of-origin marking, manuals, and carton drop testing. Label errors are the most common single reason for rejected shipments at destination.

What It Costs and What You Receive

Third-party inspection firms in China charge roughly $250 to $400 per man-day, with most DUPRO visits taking one day. Add travel for remote factories. Against an order worth $50,000 to $300,000 that is a fraction of a percent, and it is spent at the only point where a finding can still be acted on cheaply.

The deliverable is a report within 24 hours: a pass, fail, or pending verdict; defect counts sorted into critical, major, and minor; photographs of every defect with the unit identified; measurement results against your drawing; quantity verification; and the inspector's notes on line conditions. Read the photographs, not just the verdict. Inspectors work to the criteria you supply, so if your specification is thin, the report will be thin. Supply the drawing, the approved BOM, the packing spec, and a written list of what constitutes a critical defect for your product.

Where DUPRO Sits Among the Other Checks

DUPRO is one of five checkpoints, and each answers a different question.

  • Factory audit, before you order, answers whether this company can build your product at all. Covered in China factory audit.
  • First article inspection, at the start of the run, answers whether the first parts off the tooling match the drawing. See first article inspection.
  • DUPRO, mid-run, answers whether the process is staying in control now that it is running at volume with real operators.
  • Pre-shipment inspection, at 100 percent production and 80 percent packed, answers whether the finished lot is acceptable. Sampling levels and the arithmetic behind accept and reject numbers are in AQL inspection.
  • Container loading supervision, at shipment, answers whether the right goods actually went into the box.

The common mistake is treating these as alternatives. They are sequential filters, and skipping the middle one is what turns a small process drift into a full-order defect. Note also that DUPRO is where slow-developing problems appear: tool wear producing creeping flash, a cooling line that drifts and starts producing sink marks, an operator who has quietly changed the assembly sequence. Those are exactly the failure modes described in injection molding defects, and they are invisible in a first article check because the tool was fresh.

Tie It to Payment and Use the Leverage

The reason DUPRO works is commercial, not technical. The factory still holds 70 percent of your money as a receivable and wants to ship on schedule. Write into the purchase order that a DUPRO will be performed, that the factory must provide access and a workspace, and that a failed DUPRO requires a written corrective action before production continues. Costs and terms around the deposit and balance are covered in paying a Chinese factory.

Announce the inspection but agree only a window, letting the inspection firm pick the day within it. And keep your own eyes on the line between visits using the routines in managing a contract manufacturer remotely; a DUPRO is a snapshot, and weekly photo evidence fills in the rest.

Build an Inspection Plan Before Your Order Starts

Projects House writes inspection specifications for US clients producing overseas: defect classification for your specific product, drawing-based check lists, golden sample protocol, and the schedule of audit, FAI, DUPRO, and pre-shipment checks. Send your product details and factory information through our contact form.