Acceptance sampling plan for variables

Acceptance sampling for variables requires that one specifies the number of items to be sampled, and the criteria for decision making (lot sentencing) when data is collected on the quantity of interest. Usually a smaller sample size is needed than for an acceptance sampling plan for attributes. Sampling plans may control the lot percent fraction defective or control a lot parameter (usually the mean). The former are typically based on the upper specification limit (USL) or lower specification limit (LSL), on specific operating characteristic curves or the military standard 414 (civilian version ANSI/ASQC Z1.9). Tables may be found in [a1].

References

[a1]	D. Montgomery, "Introduction to statistical quality control" , Wiley (1991) (Edition: Second)