Control Quality
During Production
Our during production inspection services in China help you monitor product quality, production progress, and compliance while manufacturing is still in process.
With experienced inspectors on-site during manufacturing, ProQCChina identifies defects, deviations, and delays early — allowing corrective actions before mass production is completed and preventing costly rework, delays, or shipment failures.
Contact ProQCChinaWhen And Why Should During Production Inspection Be Conducted?
During Production Inspection (DPI), also known as DUPRO inspection, is a proactive quality control service performed while manufacturing is still in progress. This inspection is typically conducted when 20% to 80% of production is completed, allowing early detection of quality issues before mass production is finalized.
Conducting DPI at the factory in China enables inspectors to verify product workmanship, materials, production status, and compliance with approved specifications. Any deviations, defects, or delays can be identified and corrected immediately, minimizing costly rework, shipment delays, or rejected goods.
By implementing professional during production inspection services in China, importers gain real-time visibility into their supply chain, maintain strict quality standards, and significantly reduce risks before products reach the final production and shipping stages.
| Lot Size | General Inspection Levels | Special Inspection Levels | |||||
|---|---|---|---|---|---|---|---|
| I | II | III | S1 | S2 | S3 | S4 | |
| 2 to 8 | A | A | B | A | A | A | A |
| 9 to 15 | A | B | C | A | A | B | B |
| 16 to 25 | B | C | D | A | A | B | C |
| 26 to 50 | C | D | E | A | B | C | C |
| 51 to 90 | C | E | F | B | B | C | D |
| 91 to 150 | D | F | G | B | C | D | E |
| 151 to 280 | E | G | H | B | C | D | E |
| 281 to 500 | F | H | J | B | C | E | F |
| 501 to 1200 | G | J | K | C | D | E | G |
| 1201 to 3200 | H | K | L | C | D | F | G |
| 3201 to 10000 | J | L | M | D | E | G | H |
| 10001 to 35000 | K | M | N | D | E | G | J |
| 35001 to 150000 | L | N | P | D | E | H | J |
| 150001 to 500000 | M | P | Q | D | E | H | J |
| 500001 and over | N | Q | R | D | E | H | K |
| Sample Size Code Letter |
Sample Size | Acceptable Quality Levels (Normal Inspection) | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 0.065 | 0.10 | 0.15 | 0.25 | 0.40 | 0.65 | 1.0 | 1.5 | 2.5 | 4.0 | 6.5 | ||
| A | 2 | 0/1 | 0/1 | 0/1 | 0/1 | 0/1 | 0/1 | 0/1 | 0/1 | 1/2 | 1/2 | 1/2 |
| B | 3 | 0/1 | 0/1 | 0/1 | 0/1 | 0/1 | 1/2 | 1/2 | 1/2 | 1/2 | 2/3 | 2/3 |
| C | 5 | 0/1 | 0/1 | 0/1 | 0/1 | 1/2 | 1/2 | 1/2 | 2/3 | 2/3 | 3/4 | 3/4 |
| D | 8 | 0/1 | 0/1 | 0/1 | 1/2 | 1/2 | 1/2 | 2/3 | 2/3 | 3/4 | 4/5 | 4/5 |
| E | 13 | 0/1 | 0/1 | 1/2 | 1/2 | 2/3 | 2/3 | 3/4 | 3/4 | 5/6 | 5/6 | 7/8 |
| F | 20 | 0/1 | 0/1 | 1/2 | 1/2 | 2/3 | 3/4 | 3/4 | 5/6 | 5/6 | 7/8 | 10/11 |
| G | 32 | 0/1 | 1/2 | 1/2 | 2/3 | 3/4 | 3/4 | 5/6 | 5/6 | 7/8 | 10/11 | 14/15 |
| H | 50 | 0/1 | 1/2 | 2/3 | 2/3 | 3/4 | 5/6 | 5/6 | 7/8 | 10/11 | 14/15 | 21/22 |
| J | 80 | 1/2 | 2/3 | 2/3 | 3/4 | 5/6 | 7/8 | 7/8 | 10/11 | 14/15 | 21/22 | 21/22 |
| K | 125 | 2/3 | 2/3 | 3/4 | 5/6 | 7/8 | 10/11 | 10/11 | 14/15 | 21/22 | 21/22 | 21/22 |
| L | 200 | 2/3 | 3/4 | 5/6 | 7/8 | 10/11 | 14/15 | 14/15 | 21/22 | 21/22 | 21/22 | 21/22 |
| M | 315 | 3/4 | 5/6 | 7/8 | 10/11 | 14/15 | 21/22 | 21/22 | 21/22 | 21/22 | 21/22 | 21/22 |
| N | 500 | 5/6 | 7/8 | 10/11 | 14/15 | 21/22 | 21/22 | 21/22 | 21/22 | 21/22 | 21/22 | 21/22 |
| P | 800 | 7/8 | 10/11 | 14/15 | 21/22 | 21/22 | 21/22 | 21/22 | 21/22 | 21/22 | 21/22 | 21/22 |
| Q | 1250 | 10/11 | 14/15 | 21/22 | 21/22 | 21/22 | 21/22 | 21/22 | 21/22 | 21/22 | 21/22 | 21/22 |
| R | 2000 | 14/15 | 21/22 | 21/22 | 21/22 | 21/22 | 21/22 | 21/22 | 21/22 | 21/22 | 21/22 | 21/22 |
A Structured & Reliable During Production Inspection Process
Each inspection step is executed to maintain quality control during manufacturing.
Pre-Inspection Planning
Review of specifications, samples, and quality requirements.
Inspection Scheduling
Coordination with the factory to confirm production readiness.
Factory Visit
On-site assessment of production progress and conditions.
Quality Checks
Evaluation of workmanship and conformity to specifications.
Defect Identification
Detection of defects or risks impacting final product quality.
Reporting
Detailed report with findings and corrective recommendations.
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