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1)            Booking Procedure

Simply submit the informations about product such as po, specifications, and about supplier such as contact method. Please better make appointment with at least 3 working days prior to the required service date. With reference to the information given, our team will make a pre-quotation and upon receipt of your confirmation, our team will contact your supplier and arrange the service process accordingly. In the next day after the inspection completion, you will receive a detailed report together with digital photos.

2)            ANSI Sample Tables

Table I: Sample size code letters

TableII: Single sampling plans for normal inspections (Master Table)

2) Defect

This is (a) any nonconformance from a customer's requirement (b) any attribute of a product or service that fails to meet specifications (c) any state of unfitness for use. Defects are usually cataloged into four types by degree, being very serious, serious, major and minor.

3)Defect Classification

Defects detected during visual inspection are classified within 3 categories, "Critical", "Major" and "Minor" and the normal definitions are:


Any condition found which poses the possibility of causing injury or harm to, or otherwise endangering the life or safety of, the end user of the product or others in the immediate vicinity of its use.


Any condition found adversely affecting the product's marketability and sale-ability or adversely affecting its required form, fit, or function, and which is likely to result in the end user returning it to the source from which it was purchased for replacement or refund.


Any condition found which while possibly less than desirable to the end user of the product, does not adversely affect its required marketability, sale-ability, form, fit, or function and is unlikely to result in its return to the source from which it was purchased


4)Acceptable Quality Level (AQL)

An AQL, or Acceptable Quality Limit, is a probability limit chosen for a given product or process characteristic. There are normally three limits chosen, one for critical, major and minor. Usually, each of these three limits is different for each category.

The lower the number, the fewer defects can be accepted in the sample of product. When choosing AQLs, it is important that one understands the balance between setting them too low, and rejecting many shipments, and setting them too high and releasing unacceptable product. Unless specified by the client, Sino-QC will adopt the AQL as follows:


High valued products

Low valued products

Critical defects

Not allowed

Not allowed

Major defects

AQL1.0 / 1.5

AQL 2.5

Minor defects

AQL 2.5 / 4.0

AQL 4.0

5)Sampling Plan

Sino-QC recommends sampling tables to determine the number of units that will be randomly selected for evaluation. Based on the lot or batch size, code letters are assigned that cross-reference to the sample size required depending on which plan is being employed. Single normal sampling plans are the most commonly used.

If you do not have existing sampling requirements, Sino-QC will assist you in determining which plan works best for your specific needs.

Samples are checked against a detailed inspection plan for appearance, applicable functionality, packaging integrity, workmanship, etc.  If you currently do not have an inspection plan, we can assist.

Defects noted are classified as major, minor, or critical depending on inspection plans.  The acceptable quality level (AQL) is determined by totaling the defects and using the corresponding accept/reject criteria within the sampling plan.

Example of an Inspection:

The below example illustrates the procedures for utilizing the single sampling plan:

·               Product     :  Children wear

·               Batch size  :  15,000pcs

·               Standard     :  Level II

·               Sample size    :  315 pcs

·               AQL             :  Major: 2.5 & Minor 4.0

Acceptance number: 14pcs of Major & 21pcs of Minor which means either the Major defects exceed 14pcs or Minor defects exceed 21pcs or both are considered to be "Fail".

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