What AQL level should I specify for my PSI?

AQL (Acceptable Quality Level) determines how many units are sampled and what defect rate is acceptable. For most industrial and consumer goods, AQL 2.5 is standard. For critical safety or precision parts (medical, aerospace, automotive safety), AQL 1.0 or tighter is recommended. Dewin uses AQL 2.5 as the default for PSI unless the customer specifies otherwise. For high-value or safety-critical orders, we recommend AQL 1.0 with a zero-tolerance for critical defects.

Does PSI include Country of Origin verification for Section 301 tariff compliance?

Yes. Dewin's PSI service includes a Country of Origin (COO) documentation check as part of every inspection for US-bound shipments. We verify that goods are genuinely produced in Vietnam (substantial transformation, sufficient local content), that the commercial invoice, packing list, and Certificate of Origin align, and that there is no evidence of third-country transshipment or circumvention. This protects you from CBP enforcement actions and ensures you retain the $0 Section 301 tariff benefit.

Quality & Inspection Guide

Pre-Shipment Inspection (PSI)
Stop Defects Before They Cross the Ocean

Q: What is a Pre-Shipment Inspection (PSI)?

A Pre-Shipment Inspection (PSI) is a quality check performed at the factory after production is 80–100% complete but before goods are loaded for shipment. An inspector (either Dewin's on-ground team or a third-party lab) visits the factory, randomly samples finished units using AQL (Acceptable Quality Level) sampling tables, and verifies dimensions, appearance, function, labeling, and packaging against your approved specifications. PSI is your last line of defense before goods leave the factory — catching defects at the source is always cheaper than dealing with them after delivery.

Q: What is the difference between PSI, FAI, and PPAP?

FAI (First Article Inspection) happens at the start of production — it verifies the first production parts meet your specs before mass production begins. PPAP (Production Part Approval Process) is a comprehensive supplier qualification process covering process capability, FMEA, and control plans. PSI (Pre-Shipment Inspection) happens at the END of each production run — it verifies the finished goods batch is acceptable before loading. Think of it this way: FAI qualifies the process; PPAP documents the process; PSI verifies each outgoing shipment.

Q: What happens if a PSI fails?

If a PSI reveals defects above the AQL threshold, Dewin works with the factory to sort, rework, or replace the affected units before shipment. We document the failure, negotiate with the factory for corrective action at their cost, and schedule a re-inspection. If the failure is critical or systemic, we escalate to factory management and involve the Dolphin audit team for root cause analysis. Shipment is held until the batch passes. This process protects you from receiving and paying for nonconforming goods.

When goods leave Vietnam, your leverage disappears. Pre-Shipment Inspection is your last on-the-ground checkpoint — verify quality, dimensions, labeling, packaging, and Country of Origin before the container is sealed.

Request PSI Service → View FAI Guide

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Section 301 Tariff Alert: US Customs and Border Protection (CBP) increasingly scrutinizes shipments claiming Vietnam origin to avoid the 25–145% China tariff. A PSI with COO documentation verification is your proof of genuine Vietnamese manufacture — and your defense if CBP questions the shipment.

What Is Pre-Shipment Inspection?

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

An inspector visits the factory, selects a random sample of finished units using internationally standardized AQL (Acceptable Quality Level) sampling tables, and checks against your approved specifications: dimensions, appearance, function, labeling, packaging, and documentation.

The inspector produces a detailed PSI report with photos and measurements. If the batch passes, shipment proceeds. If it fails, corrective action is required before loading.

When PSI Happens in Your Order Flow

PO Issued

You place the order with factory

FAI / First Article

First production parts approved

Mass Production

Full production run in progress

PSI Triggered (80–100% done)

Inspector visits factory

Pass/Fail Decision

Ship if passed; rework if failed

Container Loading

Goods shipped to US port

US Customs Clearance

COO docs reviewed by CBP

PSI vs FAI vs PPAP

Three quality tools. Three different moments. All three working together protect your supply chain.

Attribute	PPAP	FAI	PSI ← This Guide
When it happens	Before mass production begins	First production parts	End of each production run
What it checks	Process capability, FMEA, control plan, documentation	First parts vs engineering drawing	Finished goods batch vs approved specs
Who is checked	Supplier process & system	First article parts (physical)	Random sample of finished units
Frequency	Once per part/process qualification	Once per new tool/supplier/change	Every shipment (or periodic)
AQL sampling	No	No — all dimensions measured	Yes — ISO 2859 / MIL-STD-1916
COO documentation check	Partial	Partial	Yes — full COO verification
Managed by Dewin	✅ Yes	✅ Yes	✅ Yes

→ PPAP Guide → FAI Guide

What Dewin PSI Covers

Dewin's on-ground team follows a structured 8-category PSI checklist. Every inspection produces a photographic report you can share with your team and customs broker.

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Dimensional Verification

✓ Critical dimensions vs drawing
✓ GD&T callout spot checks
✓ Caliper / CMM / VMM measurement
✓ Tolerance conformance record

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Visual & Cosmetic

✓ Surface finish & texture
✓ Color comparison (delta-E where applicable)
✓ Burrs, scratches, dents, voids
✓ Plating / coating uniformity

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Functional Testing

✓ Fit & assembly check
✓ Torque / pull-out / load test
✓ Electrical continuity (where applicable)
✓ Sealing & leak tests

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Packaging & Labeling

✓ Inner / outer carton condition
✓ Label accuracy & legibility
✓ Part numbers & revision levels
✓ Qty per carton vs PO

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Documentation Check

✓ Material certs vs spec
✓ RoHS / REACH compliance docs
✓ Heat treatment / plating records
✓ Test reports from factory QC

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Country of Origin (COO)

✓ Certificate of Origin review
✓ Substantial transformation confirmation
✓ No transshipment evidence
✓ Invoice / packing list alignment

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AQL Sampling

✓ ISO 2859-1 / MIL-STD-1916 tables
✓ AQL 2.5 standard (AQL 1.0 optional)
✓ Sample size per order qty
✓ Accept/reject decision documented

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Photographic Evidence

✓ Factory floor production photos
✓ Packing process photos
✓ Defect closeups (if found)
✓ Final sealed carton photos

AQL Sampling Reference

AQL (Acceptable Quality Level) determines how many units are inspected and what defect rate is acceptable. Dewin defaults to AQL 2.5 General Inspection Level II — the global industry standard for most manufactured goods.

Order Qty	Sample Size	AQL 2.5 — Accept If	Reject If	AQL 1.0 (Critical)
51–90 units	13	0 defects	1+ defect	Accept 0 / Reject 1
91–150 units	20	1 defect	2+ defects	Accept 0 / Reject 1
151–280 units	32	2 defects	3+ defects	Accept 0 / Reject 1
281–500 units	50	3 defects	4+ defects	Accept 1 / Reject 2
501–1,200 units	80	5 defects	6+ defects	Accept 2 / Reject 3
1,201–3,200 units	125	7 defects	8+ defects	Accept 3 / Reject 4
3,201–10,000 units	200	10 defects	11+ defects	Accept 5 / Reject 6

Abbreviated reference. Based on ISO 2859-1 General Inspection Level II. Defect counts shown are for Major defects. Critical defects (safety, functional failure) are always zero-tolerance.

Why PSI Matters for Vietnam Sourcing

The cost of fixing a defect explodes once goods leave the factory. PSI catches problems when correction is still cheap.

Fix Cost: Low

At the Factory (Before PSI Fails)

• Sort good/bad units in-factory
• Rework at factory cost
• Replace batch before loading
• Factory bears cost for their defect

Fix Cost: Medium–High

In Transit / At Port

• Cargo recall or divert
• Re-inspection at warehouse
• Customs holds add delay & storage fees
• You bear most costs at this stage

Fix Cost: Very High

After US Delivery

• Sort labor at your facility
• Return shipping to Vietnam
• Customer complaints / chargebacks
• Production line downtime if parts missing

🛡️ PSI + Section 301 Tariff Protection

With 25–145% Section 301 tariffs on Chinese-origin goods, CBP is aggressively investigating Vietnam-origin claims for signs of tariff circumvention. A Dewin PSI report with COO documentation gives you:

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COO Documentation Package

Certificate of Origin, commercial invoice, packing list — all verified and aligned before shipment

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Substantial Transformation Evidence

Production photos, process records, and BOM verification showing genuine Vietnamese manufacture

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CBP Defense Package

If CBP questions the shipment, your PSI report is documented evidence of due diligence

Dewin's 6-Step On-Ground PSI Process

No remote or paper-based inspection. Dewin's team physically visits the factory.

Inspection Booking & Spec Upload

You share your approved drawings, specifications, AQL level, and any special requirements. Dewin schedules the inspector with a 48–72 hour lead time after production completion notification.

Factory Visit & Production Verification

Inspector arrives when production is 80–100% complete. Confirms qty produced vs PO, reviews factory's internal QC records, checks raw material certs and process traveler.

Random Sampling per AQL Tables

Inspector selects units randomly from finished goods inventory (not factory-picked). Sample size per ISO 2859-1 General Level II. For critical parts, AQL 1.0 with 100% check of critical features.

8-Category Inspection Execution

Dimensional checks, visual inspection, functional testing, labeling/packaging verification, documentation review, and COO documentation verification. All findings photographed and recorded.

Pass/Fail Decision & Report

Inspector issues Pass/Fail decision on-site. Full report with photos, measurements, AQL tally, and defect classification (critical / major / minor) delivered within 24 hours. You receive the report before shipment is authorized.

Corrective Action or Ship Authorization

If Pass: shipment authorization issued. If Fail: Dewin negotiates corrective action with factory, re-inspection scheduled. If critical defects found, Dolphin audit escalation process triggered.

PSI Requirements by Manufacturing Process

Each manufacturing process has process-specific inspection points. Dewin's inspectors are trained on all major processes in our factory network.

Process	Key PSI Checks	Equipment Used	Section 301 Tariff (China)
CNC Machining	Critical dimensions, surface finish (Ra), thread gauging, GD&T callouts, material cert verification	Caliper, CMM/VMM, thread gauge, profilometer	25% (HTS Ch. 73/84)
Die Casting	Wall thickness, porosity check, dimensional conformance, surface finish, plating adhesion	Caliper, X-ray (if specified), visual standard	25% (HTS Ch. 76)
Injection Molding	Color delta-E, sink marks, warpage, dimensions, gate vestige, labeling	Color comparison machine, caliper, visual standard	25–145% (HTS Ch. 39/85)
Sheet Metal	Bend angles, hole positions, flatness, edge finish, surface coating	Angle gauge, caliper, coating thickness gauge	25% (HTS Ch. 73)
Stamping	Part dimensions, burr height, flatness, material hardness, plating / e-coat	Caliper, hardness tester, coating gauge	25% (HTS Ch. 73)
Forging	Profile dimensions, grain flow verification, mechanical properties, heat treatment cert	Caliper, hardness tester, material cert review	25% (HTS Ch. 73)
Assembly	Sub-component fit, torque values, function test, BOM conformance, labeling/packaging	Torque wrench, functional fixture, visual checklist	25–145% (varies by HTS)

All tariff rates shown are Section 301 China-origin rates. Vietnam-origin goods: $0 Section 301 tariff. Subject to change — verify current rates with your customs broker.

Dewin PSI vs Unverified Sourcing

What happens when you source without an on-ground inspection partner?

Factor	Dewin PSI	No PSI / Self-Managed
Defect discovery	At factory — before loading	After delivery — too late
Corrective action cost	Factory bears cost of their defects	You bear return shipping + sorting
AQL methodology	ISO 2859-1 standardized sampling	Ad hoc or none
COO documentation check	Full review before shipment	No review — CBP risk
Photographic evidence	Full photo report every shipment	Factory self-reported (unverified)
Section 301 defense	Documented due diligence package	No documentation if CBP audits
Lead time impact	24-hour report turnaround	Weeks of dispute after delivery
Factory accountability	Non-conformance on record	Factory denies after shipment

Pre-Shipment Inspection FAQ

What is a Pre-Shipment Inspection (PSI)?

A PSI is a quality check performed at the factory after production is 80–100% complete but before goods are loaded for shipment. An inspector randomly samples finished units using AQL tables and verifies dimensions, appearance, function, labeling, packaging, and Country of Origin documentation.

What is the difference between PSI, FAI, and PPAP?

FAI verifies the first production parts at the start of production. PPAP documents your supplier's process capability before mass production. PSI verifies each finished goods batch at the END of each production run, before loading. All three together give you complete quality coverage.

What AQL level should I specify?

AQL 2.5 General Level II is the global standard for most manufactured goods. For safety-critical or precision parts (medical, aerospace, automotive), specify AQL 1.0 or tighter. Dewin defaults to AQL 2.5 and can tighten to AQL 1.0 on request.

Does PSI include Country of Origin verification for Section 301 compliance?

Yes. Every Dewin PSI for US-bound shipments includes COO documentation review — verifying Certificate of Origin, commercial invoice, packing list alignment, and evidence of substantial transformation in Vietnam. This protects you if CBP questions the shipment.

What happens if a PSI fails?

If defects exceed the AQL threshold, Dewin works with the factory to sort, rework, or replace the affected units before shipment. We document the failure and negotiate corrective action at the factory's cost. Shipment is held until the batch passes re-inspection.

Don't Let Defects Cross the Ocean

Dewin's on-ground team in Vietnam conducts PSI for every shipment — with AQL sampling, COO verification, and a 24-hour photographic report. Your last line of quality defense before the container is sealed.

Request PSI Service → Learn About Dolphin Audit

✓ On-ground team in Vietnam ✓ 179+ audited factory network ✓ 24-hour PSI report ✓ Section 301 COO documentation

Pre-Shipment Inspection (PSI) Stop Defects Before They Cross the Ocean