Table 1 : Sample Size Code Letters

Table 2 : Single Sampling Plans For Normal Inspection
(Master Table)

Definitions :

Acceptance Number (Ac) - it is the maximum number of defects or defective units in the sample that will permit acceptance of a lot or batch.

AQL - Acceptable Quality Limit. It is the quality level that is the worst tolerable process average when a continuing series of lots is submitted for acceptance sampling.

Defect - a departure from the requirements specified in the contract, specification, or other approved product documentation which has been isolated to a given material, assembly, component or part. Defects fall within three categories as follows :

1. Critical Defect - a defect that judgment and experience indicate is likely to result in hazardous or unsafe conditions for individuals using, maintaining, or depending upon the product.
2. Major Defect - a defect other than critical, that is likely to result in failure, or to reduce materially the usability of the product for its intended purpose.
3. Minor Defect - a defect that is not likely to reduce materially the usability of the unit or product for its intended purpose, or is a departure from established standards having little bearing on the effective use or operation of the unit.

Lot or Batch - The term lot or batch shall mean "inspection lot" or "inspection batch" i.e., a collection of units of product from which a sample is to be drawn and inspected to determine conformance with the acceptability criteria, and may differ from a collection of units designated as a lot or batch for other purposes (e.g., production, shipment, etc.).

Rejection Number (Re) - is the minimum number of defects or defective units in the sample that will cause rejection of the lot represented by the sample.

Single Sampling Plan - is a type of sampling plan by which the results of a single sample from an inspection lot are conclusive in determining acceptability. The number of sample units inspected shall be equal to the sample size given by the plan.

Example On How To Use The Above Tables :

1. Lot or batch size : 1,000 (Please see Table 1)
2. General Inspection Level used : II (Please see Table 1)
3. In Table 1 above, the intersection of Lot or batch size (1,000) and General Inspection Level II is “J”.
4. In Table 2 above, we can see that Sample size code letter “J” corresponds to a sample size of “80”.
5.  AQL for CRITICAL DEFECT = NOT ALLOWED , MAJOR DEFECT = 1.5 and MINOR DEFECT = 2.5
6. Ac & Re for CRITICAL DEFECT are 0 and 1 respectively
7. Ac & Re for MAJOR DEFECT are 3 and 4 respectively and
8. Ac & Re for MINOR DEFECT are 5 and 6 respectively