Contents
- Index
Single Sampling Plans for Defects Per Quantity
Characteristic:
Defects per quantity
Assumptions:
(1) Representative sample
Parameters:
n = sample size, real number satisfying n>0
a = accept number, integer satisfying a³0
Units of measure for n = length, area, volume or some other quantity of material
Sometimes a third parameter, r = reject number, is given. The parameter r is always equal to a+1 and is redundant.
Procedure:
(1) Take a representative sample of size n from the lot to be inspected.
(2) Count the number of defects in the sampled quantity.
(3) If this count is less than or equal to a, accept the lot. Otherwise reject the lot.
Sometimes the accept or reject decision is determined before all the sample is inspected. In this case, the inspection can be curtailed. For single sampling plans for defects you can only curtail on rejection as follows:
Curtail on Rejection: Stop the inspection and reject as soon as a+1 defects are found.