There are several levels of inspections appropriate to the different stages of production. The level and the consignment size will determine the size of the sample to be randomly selected.

The levels used for the 3 pre-shipment inspections are as follows:

– Initial Production Check (IPC) – Single Sampling Plan General Level I
– During Production Check (DUPRO) – Single Sampling Plan General Level I
– Final Random Inspection (FRI) – Single Sampling Plan General Level II

If a tighter inspection plan is needed for special cases where stricter controls are required, Level III may be applied. Level III generally means that a larger sample size will be checked, of which a smaller proportion is allowed to be defective.

Level S3 is a special level used in conjunction with Levels I, II and III. Level S3 is used for field tests and performance measurements where it would not be practical to perform such tests on larger sample sizes