Code of Federal Regulations (alpha)

CFR /  Title 7  /  Part 42  /  Sec. 42.132 Determining cumulative sum values.

(a) The parameters for the on-line cumulative sum sampling plans for AQL's applicable to origin inspection are as follows: --------------------------------------------------------------------------------------------------------------------------------------------------------

Type of inspection

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Acceptable quality levels Normal Tightened Reduced

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T L S T L S T L S--------------------------------------------------------------------------------------------------------------------------------------------------------0.25........................................................... 0.05 0.95 0.35 0.1 0.9 0.3 0 0 01.5............................................................ 0.5 2 1 0.8 1.6 0.4 0.5 0.5 06.5............................................................ 2 3 1 2.5 3 1 1 2 1--------------------------------------------------------------------------------------------------------------------------------------------------------

(b) At the beginning of the basic inspection period, the CuSum value is set equal to the starting value (``S'') for the specified CuSum plan. The CuSum value is then determined for each consecutive subgroup as follows:

(1) Add the number of defects for the present subgroup to the CuSum value of the previous subgroup.

(2) Subtract the subgroup tolerance (``T'').

(3) The CuSum value is reset in the following situations; however, determine portion of production acceptability (see Sec. 42.133) prior to resetting the CuSum value:

(i) Reset the CuSum value to zero (0) if the CuSum value is less than zero (0).

(ii) Reset the CuSum value to the acceptance limit (``L'') if the CuSum value exceeds the acceptance limit (``L'').