Introduction
“Quality control” is often used loosely, as if it were a single step. In practice, quality control is a sequence of checkpoints running from before production begins to after the shipment is delivered.
This article walks through the full process, so a buyer can see what is happening at each stage and where their input matters.
Stage 1 — Specification
Quality control begins before any production. The specification document defines what the finished product must look like, how it must perform, and what defects are and are not acceptable.
Elements to include:
- Dimensions and tolerances
- Materials, grades, and finishes
- Functional performance criteria if applicable
- Packaging requirements
- Defect classifications (critical / major / minor) with examples
- Acceptable Quality Level (AQL) for each defect class
A written specification is what the factory produces to, the inspector inspects against, and the buyer disputes on. Without one, quality is negotiable after the fact.
Stage 2 — Sample Approval
Before production, the buyer signs off on one or more samples. Each sample round tests both the product and the supplier’s willingness to adjust.
The approved sample becomes the reference for production. Every subsequent quality question is answered against it.
Stage 3 — Raw Material Inspection (Optional)
For higher-value or technical products, an inspection at the raw material stage confirms the factory purchased the specified materials rather than substitutes. This is skippable for simple products, worth including for anything with material-driven quality.
Stage 4 — During-Production Inspection (DPI)
When production is 20–40% complete, an inspector visits the factory and checks the in-process goods. Catching a systematic defect at this stage means the remaining 60–80% of production can be corrected. Catching it at pre-shipment means reworking the entire batch.
DPI is optional for small orders and standard for larger or higher-risk ones.
Stage 5 — Pre-Shipment Inspection (PSI)
The main inspection point — described in detail in the pre-shipment inspection guide. This is the last checkpoint before the balance is paid.
Stage 6 — Container Loading Supervision
For higher-value shipments, an inspector supervises the container loading itself. This confirms the inspected goods are the goods actually shipped, and that loading damage is prevented.
Stage 7 — Post-Delivery Feedback
After the shipment arrives, the buyer records the actual defect rate against expectation. Photos, defect counts, and units sold-through affect the next order — either as improvement feedback or as commercial leverage in negotiation.
Suppliers who receive documented feedback improve. Suppliers who receive none stay the same.
Which Stages Actually Matter For Your Order
Not every order needs every stage. A minimum viable quality process:
- Written specification with defect classification
- Sample approval before production
- Pre-shipment inspection
- Post-delivery feedback record
Add DPI and material inspection when product risk or order value warrants them.
FAQ
Can a sourcing partner run the entire quality process? Yes. Hansen runs the specification, sample approval, in-process checks, and pre-shipment inspection as an integrated service.
How much does the full process cost? Typically 3–6% of order value for a mid-sized order. The exact cost scales with product complexity and how many inspection stages are included.
Is quality control worth it on a small first order? Especially on a small first order. That is the order where you learn what this supplier’s real quality looks like.
Run A Quality Process On Your Production
Good quality is a process, not luck. If you would like Hansen to run that process, see China Quality Control or start a project.