- CRI (Critical):​ A defect that poses a safety risk to the user or violates mandatory regulations. For example, small parts on a toy that easily detach posing a choking hazard, or electrical leakage in an appliance. The AQL is typically set to 0 (not allowed), meaning it is absolutely unacceptable.
- MAJ (Major):​​ A defect that may cause product failure, affect primary function, or severely impact salability and usability. For example, a hole in a critical area of a garment, an electronic product that fails to power on, or an incorrect product model. Customer tolerance for such defects is usually very low.
- MIN (Minor):​ A defect that does not significantly affect the product's function or lifespan but is a deviation from quality standards in appearance or workmanship. For example, minor scratches, slight color deviation, or loose threads in non-critical areas. The AQL value for such defects is typically set more leniently.

The AQL value (e.g., 2.5) does not​ represent the required defect rate for the "sample," but is a statistical definition of the "acceptable upper limit" for the quality level of the "entlot."

Let's explain with an analogy:

a) Core Logic is "Inferring the Whole, Not Judging the Sample"
The purpose of sampling inspection is not to conclude on these 200 samples, but to use the condition of these 200 samples to scientifically infer the quality level of the entire batch (e.g., 10,000 pieces). AQL=2.5 means: We set a standard, hoping that for batches judged as acceptable, the actual defect rate of the entire lot has a probability greater than 95% of being no higher than 2.5%.

b) Why is a 5% defect rate allowed in the sample?
This reflects the "sampling risk" and "confidence level" in statistics. To work efficiently with a reasonable sample size, sampling plans allow for certain risks. Even if the true defect rate of the entire lot is exactly 2.5%, the number of defects in our sample of 200 has a probability of fluctuating higher (e.g., 5%). This sampling plan (200 pieces, Ac=10, Re=11) is designed to balance the risks for the producer (good lot wrongly rejected) and the consumer (bad lot wrongly accepted), achieving an internationally recognized balance.

c) The True Meaning of "Acceptance Number Ac=10"
When you find 10 or fewer defects in a sample of 200, this result does not​ say "the defect rate of the entire lot is 5%." It says, "Under the preset statistical risk, there is insufficient evidence to prove that the defect rate of the entire lot exceeds the 2.5% upper limit,"​ therefore it is judged as "Accept."

Conversely, if 11 (Re=11) or more defects are found, then statistically there is sufficient confidence to say that the quality of the entire lot is likely worse than the AQL 2.5 standard, therefore it is judged as "Reject."

In summary:
i. You are correct: Under AQL 2.5, inspecting 200 pieces allows for up to 10 defects (5%) in the sample.
ii. This is not contradictory: AQL 2.5 is not the standard for the sample defect rate, but a statistical threshold​ for the quality level of the entire lot. The 5% defect rate in the sample is the decision-critical point​ set under this statistical rule to judge whether the entire lot is likely better than the 2.5% threshold.

Not exactly a simple percentage. The sample size is determined jointly by the lot size​ and the selected inspection level​ (usually General Level II), found by consulting the sampling tables attached to standards like ISO 2859-1 / ANSI/ASQ Z1.4. As the total quantity increases, the sample size increases accordingly, but the increase is not linear; the proportion of the sample size to the larger lot becomes progressively smaller. Please refer to the AQL tables for specifics.

No, a passing AQL inspection does not​ mean the entire batch is 100% compliant with the established standard..

1). The Nature of the Inspection Method:​ AQL is a sampling inspection, not a 100% inspection. It infers the quality of the entire batch by checking a portion (the sample). Therefore, it cannot detect issues in every individual product that was not sampled.
2). The Specific Meaning of "Compliance":​ Within the AQL statistical framework, "passing inspection" (i.e., being judged as "Accept") truly means: under the preset statistical risk (typically a 5% consumer's risk), there is insufficient evidence to prove that the defect rate of the entire batch exceeds your set AQL standard (e.g., MAJ 2.5). This is not​ a 100% certain, absolute declaration of compliance, but rather a probabilistic conclusion with high confidence (e.g., 95%).
3). Inherent Risk Exists:​ The AQL scheme is designed to balance the producer's risk (rejecting a good lot) and the consumer's risk (accepting a bad lot). A passing inspection means the risk of "wrongly accepting a bad lot" is controlled at an acceptably low level (e.g., 5%), but this risk is not eliminated. Therefore, there remains a small probability that an accepted batch's actual quality is worse than your set standard.

Summary:
A passing AQL inspection does not​ provide an absolute guarantee of 100% compliance with the standard. It provides a scientifically statistical quality assessment report with high confidence, indicating that the batch most likely​ (e.g., with 95% confidence) meets or exceeds your established AQL quality limit. This is an industry-standard method that achieves the optimal balance between quality control and inspection cost.

DUPRO is the best choice when you need to proactively control the production process to avoid large-scale quality issues. It is applicable when:

- Order quantity is large, and the production cycle is long.
- The product process is complex, or potential quality issues have been identified early in production.
- You wish to assess the production line status, semi-finished product quality, and process consistency when production is approximately 20%-80% complete, allowing sufficient time for correction and avoiding final delivery delays.

You should choose PSI when you need to conduct a final check on finished goods ready for delivery. It applies when:

- Products are 100% complete, packed, and ready for shipment (typically with over 80% of goods in the warehouse).
- You need a comprehensive verification against order requirements for quantity, workmanship, function, appearance, packaging, shipping marks, etc., to ensure bulk quality matches samples or specifications.
- This is the most commonly used and comprehensive finished goods inspection method, aiming to prevent the shipment of entire batches of non-conforming products.

CLS service should be used when you need independent verification of the loading process to ensure goods are loaded accurately, safely, and in full quantity. It primarily addresses the following risks:

- Goods Mix-up or Short-loading:​ Verifies that loaded goods match shipping documents, preventing mixing with other order products or quantity shortages.
- Improper Loading Operations:​ Supervises the loading process, checks container condition, ensures proper stacking to avoid damage during transit from crushing or humidity.
- Preventing "Bait-and-Switch" or Fraud:​ As an independent third party, supervises and documents the entire process from warehouse pickup to container sealing, providing reliable evidence.

Typically, after confirming inspection requirements, arranging, and completing the on-site inspection, we will provide a detailed English inspection report within 24 hours. The overall process is efficient, ensuring you can make timely decisions.

A complete inspection report typically includes: Inspection Summary, Product & Order Information, Inspection Standards (AQL), Detailed Inspection Results (quantity, dimensions, function, appearance, packaging, safety tests, etc.), Defect Classification Statistics, Clear On-site Photos (including defect close-ups, packaging, marks), and the Final Conclusion (Pass/Pending/Fail) and Recommendations.

If the inspection fails, please don't worry. Our report will clearly list all defects and provide risk analysis and professional advice. Based on the report, you can:

- Negotiate with the supplier for rework or sorting.
- Authorize us to conduct a Re-inspection After Rework​ to verify the effectiveness of corrective actions.
- Make commercial decisions such as changing suppliers, requesting a discount, or canceling the order based on objective third-party data to minimize losses.

The process is very simple: You just need to register for a free account on our company website. Once the account is activated, you can place orders directly through the online platform. If needed, you can also contact us via email, providing basic requirements such as product information, inspection location, supplier contact details, inspection standards (e.g., AQL), and desired inspection date. Our account manager will quickly provide you with a quotation and service proposal. After confirmation, we will coordinate to arrange a professional local inspector to execute the task.