Quality & Inspection Guide

Pre-Shipment Inspection (PSI)
On-Ground Verification Before Your Goods Leave Vietnam

Dewin's team physically visits the factory. We check finished goods against your specs — dimensions, appearance, function, packaging, and COO documentation — before the container is sealed. Real photos. Real measurements. 24-hour report.

179+ Audited Factories 1,700+ Real Factory Photos 50-Point Dolphin Audit 16+ Free Trade Agreements On-Ground Team in Vietnam

What Is Pre-Shipment Inspection?

Pre-Shipment Inspection (PSI) — also called Final Random Inspection (FRI) — is an independent quality check performed at the factory when production is 80–100% complete and before goods are loaded into containers for export.

Dewin's on-ground team selects a random sample of finished units using internationally standardized AQL (Acceptable Quality Level) sampling tables, and inspects against your approved specifications: dimensions, appearance, function, labeling, packaging, and documentation.

Within 24 hours, you receive a full photographic PSI report. If the batch passes, shipment proceeds. If it fails, the factory corrects before loading — at their cost.

Order Flow — Where PSI Fits

1
PO Issued
Buyer places the order
2
FAI Approval
First production parts verified
3
Mass Production
Full production run in progress
4
PSI (80–100% done)
Dewin team visits the factory
5
Pass/Fail Decision
Ship if passed; rework if failed
6
Container Loading & Export
Goods shipped to buyer's port

Dolphin Audit + PSI — Dual-Layer Quality Protection

Dewin's quality system operates on two levels. The Dolphin Audit qualifies the factory. PSI verifies each shipment. Together, they close every quality gap.

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Dolphin Audit

Factory-level qualification. Done once (refreshed annually). Scores the factory's quality system.

  • 50-point scoring across 5 pillars
  • Quality System & Certifications
  • Equipment Inventory & Calibration
  • Process Control & Documentation
  • Workforce Competency
  • Facilities & Safety Compliance
Learn about the Dolphin Audit →
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Pre-Shipment Inspection (PSI)

Order-level verification. Done every shipment (or periodic). Verifies each batch actually conforms.

  • AQL random sampling (ISO 2859-1)
  • Dimensional verification
  • Visual & cosmetic check
  • Functional testing
  • Packaging & labeling audit
  • COO documentation review

Dolphin Audit Pillars × PSI Relevance

Dolphin Audit Pillar What It Qualifies in the Factory How It Enables Better PSI
Quality System & Certifications ISO 9001 / IATF 16949 / AS9100 status, QMS documentation, internal audit history Factory QC records are reliable; PSI inspector can reference internal inspection data
Equipment & Calibration Metrology equipment on-site (CMM, VMM, hardness tester, gauges), calibration certs Dewin PSI can use factory's own calibrated instruments, reducing inspection cost and time
Process Control & Documentation Process traveler, work instructions, inspection plans, SPC records Enables PSI to cross-check production records vs physical parts — catch process drift early
Workforce Competency Operator training records, QC inspector qualifications, 5S discipline Trained operators produce fewer defects; PSI acts as statistical verification of process output
Facilities & Safety Compliance Clean room, ESD controls, environmental conditions, customs documentation COO documentation and FTA certificate preparation traceable to factory-level compliance records

What Dewin PSI Covers

Every PSI follows Dewin's 8-category inspection checklist. You receive a full photographic report within 24 hours.

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Dimensional Verification

  • Critical dimensions vs drawing
  • GD&T callout spot checks
  • Caliper / CMM / VMM records
  • Tolerance conformance evidence
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Visual & Cosmetic

  • Surface finish & texture
  • Color delta-E (where applicable)
  • Burrs, scratches, voids, cracks
  • Plating / coating uniformity
⚙️

Functional Testing

  • Fit & assembly check
  • Torque / pull-out / load test
  • Electrical continuity (electronics)
  • Sealing & leak checks
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Packaging & Labeling

  • Inner / outer carton condition
  • Label accuracy & legibility
  • Part numbers & rev levels
  • Qty per carton vs PO
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Documentation

  • Material certs vs spec
  • RoHS / REACH compliance docs
  • Heat treatment / plating records
  • Factory QC test reports
🌏

Country of Origin

  • Certificate of Origin review
  • Substantial transformation check
  • No transshipment evidence
  • Invoice / packing list alignment
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AQL Sampling

  • ISO 2859-1 Level II tables
  • AQL 2.5 standard (1.0 optional)
  • Sample size by order qty
  • Accept/reject documented
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Photographic Evidence

  • Factory floor production photos
  • Packing process photos
  • Defect closeups (if any found)
  • Sealed carton confirmation

Dewin's 6-Step PSI Process

No remote inspections. No paper-based self-reporting. Our team physically visits the factory.

01

Inspection Booking

You share drawings, specs, AQL requirement, and production completion timeline. Dewin schedules the inspector within 48–72 hours of production completion notification.

02

Factory Visit & Production Verification

Inspector confirms qty produced vs PO, reviews factory's own QC records and material certs, and verifies the correct factory (not a subcontractor) is producing.

03

AQL Random Sampling

Inspector independently selects sample units from finished goods inventory. Sample size per ISO 2859-1 General Level II. Not factory-selected — truly random.

04

8-Category Inspection

Dimensional, visual, functional, labeling, packaging, documentation, COO verification, and photographic evidence — all completed in a single factory visit.

05

24-Hour Report Delivery

Full PSI report with photos, AQL tally, defect classification (critical / major / minor), and Pass/Fail decision delivered before shipment authorization.

06

Ship Auth or Corrective Action

Pass → shipment authorized. Fail → corrective action negotiated at factory cost, re-inspection scheduled. Critical defects trigger Dolphin audit escalation.

Dewin PSI vs Unverified Sourcing

What buyers experience when they skip on-ground inspection.

Factor Dewin PSI No PSI / Self-Managed
Defect discovery timing At factory — before loading After delivery — too late to act cheaply
Corrective action cost Factory bears cost for their defects Buyer bears sorting + return shipping
AQL methodology ISO 2859-1 standardized Ad hoc or none
Inspection independence Dewin team — neutral, buyer-aligned Factory self-report — conflict of interest
COO verification Full review before shipment No review — tariff risk if CBP audits
Photographic evidence Full photo report per shipment Factory self-reported, unverified
Dolphin audit integration PSI escalates to Dolphin team if critical defects found No escalation path — issues repeat
FTA documentation readiness CPTPP / EVFTA / RCEP / UKVFTA docs verified No verification — FTA benefit at risk

PSI + FTA COO Documentation

Vietnam's 16+ Free Trade Agreements give buyers significant duty advantages — but only if COO documentation is correct. Dewin PSI includes FTA document verification.

CPTPP
USA*, Canada, Australia, Japan, Singapore, and 6 others
Rule of Origin: Regional Value Content (RVC) ≥ 40% or Change in Tariff Classification

* US not yet a CPTPP member — most relevant for CA, AU, JP, SG buyers

EVFTA
27 EU member states
Rule of Origin: Sufficient processing / substantial transformation in Vietnam

Strong duty reductions on industrial goods — growing fast since 2020 ratification

RCEP
China, Japan, South Korea, Australia, ASEAN members
Rule of Origin: RVC ≥ 40% or Change in Tariff Heading (CTH)

Largest FTA by GDP coverage — covers most APAC buyer countries

UKVFTA
United Kingdom
Rule of Origin: Sufficient processing in Vietnam per product-specific rules

Post-Brexit Vietnam-UK bilateral agreement, in force from 2021

Dewin PSI includes verification that your Certificate of Origin, commercial invoice, and packing list satisfy the relevant FTA rule of origin — protecting your duty preference claim.

Pre-Shipment Inspection FAQ

What is Pre-Shipment Inspection (PSI)?
PSI is a quality check performed at the factory when production is 80–100% complete and before goods are loaded for shipment. Dewin's on-ground team visits the factory, randomly samples finished units per AQL tables, and verifies dimensions, appearance, function, labeling, packaging, and COO documentation. A full photographic report is delivered within 24 hours.
How does PSI connect to the Dolphin Audit?
The Dolphin Audit is a one-time factory qualification scoring the factory's quality system across 5 pillars — it happens before a factory joins Dewin's network. PSI is an order-level verification happening every shipment from an already-qualified factory. Together they provide dual-layer protection: the factory is pre-screened to be capable; PSI verifies each batch is actually conforming.
Which factories in Dewin's network support in-house metrology for PSI?
Six Dewin-audited factories have in-house metrology: NAPEC (3D CMM), HDP (2D VMM), Huynh Duc (3D CMM), Hirata (dual 2D VMM), Ming Chuan (color comparison machine), and Lidovit (hardness testing + digital warehouse). For other factories, Dewin coordinates with independent QC labs in the same industrial zone.
Does Dewin PSI verify COO documentation for FTA and tariff compliance?
Yes. Every Dewin PSI includes COO documentation review — verifying Certificate of Origin, commercial invoice, packing list alignment, and evidence of substantial transformation in Vietnam. This protects buyers claiming FTA duty preferences (CPTPP, EVFTA, RCEP, UKVFTA) and US importers relying on Vietnam's $0 Section 301 tariff status.

Quality Verified Before It Leaves Vietnam

Dewin's team physically visits your factory. We check finished goods against your specs, sample per AQL tables, verify COO docs, and deliver a full photographic report — all before the container is sealed.

✓ 179+ audited factories ✓ On-ground team visits factory ✓ 24-hour PSI report ✓ COO + FTA doc verification