A defect found mid-run costs a fraction of the same defect found at the port. That single fact is the business case for a during-production inspection, and the gap between the two costs grows with every week the factory keeps working. This page puts numbers on that gap and explains when to place the DPI window on your order.

The cost-of-defect curve, with a worked example

Take a 5,000-unit order of consumer electronics at $11 per unit FOB, shipping in six weeks.

• Found at DPI (25% complete): the inspector samples 1,250 finished units and finds a 7% major-defect rate — scratched housings from an unguarded conveyor. Rework cost for 88 units at roughly $0.80 each: about $70, plus a foam pad on the line that afternoon. The remaining 3,750 units are produced with the fix already in place.
• Missed at DPI: the same 7% applies to the full run — 350 defective units packed and shipped. After arrival the numbers look different: returns and customer service at roughly $9 per affected unit all-in (return freight, refund handling, repack or disposal) — about $3,150, before marketplace penalties, cancelled reorders or a damaged review page are counted.

Roughly $70 against $3,150 — a 45-to-1 spread — and the only variable is when the defect was found. DPI exists to keep you on the cheap end of that curve.

Placing the DPI window

• Timing: book when 20–30% of the order is complete. Too early and there is nothing meaningful to sample; too late and the economics above have already evaporated.
• Lead time: two to three working days’ notice is comfortable anywhere in our national coverage; urgent mid-run visits in major clusters can often be arranged sooner.
• Duration: a standard man-day covers sampling, on-site tests and the report groundwork for most orders; large or complex orders may take longer, agreed when we quote.
• Long runs: a second DPI later in the run verifies that early corrective actions held — the second visit re-checks the exact findings of the first.

What the inspector watches between the units

Sampling is only half the job. A DPI also reads the production system around the sample: actual output rate against the schedule the factory promised, machine settings and calibration at the stations causing defects, whether rejected units are segregated or quietly flowing back into carts, and whether the factory’s own inline QC is inspecting or just stamping. Root causes get named in the report — operator handling, material lot, tooling wear — so your corrective conversation with the supplier starts from facts.

Findings that show up most often mid-run

• A defect cluster traced to one station, one shift or one material lot — narrow causes are cheap causes.
• Packing materials not yet on site while the finish date holds, which quietly costs a week.
• Semi-finished stock exposed to dust, moisture or handling damage between processes.
• Sub-contracted processes the factory never mentioned at booking.
• Colour or finish drift between production batches that no single-unit check would reveal.

The report you receive

Within 24 hours, in English: verdict against your AQL, defect counts by severity with photos, measurement records, production status with an honest finish-date forecast, and the corrective actions expected before the next visit or the final pre-shipment inspection. Where a DPI follows an IPC, the earlier measurement baseline is used so drift is visible in numbers, not adjectives.

Mid-run corrections also have a home at CGF: the same company that runs your DPI operates a 2,000+ m² rework and warehousing base in Dongguan, with 95 inspectors nationwide behind it. The home page maps the full one-stop service station, inspection to dispatch.

Book a mid-run check

Send the PO, spec and production schedule by email to kelly@cgfiinspection.com; the WhatsApp/WeChat line, 86-15306546882, reaches the same coordinator — or use the contact page. A fixed-fee quote and a proposed inspection window come back within one working day.