Sampling plans for beta distributed compositional fractions

• Compositional quality measurement and assurance are covered.
• Beta distribution based sampling plans are discussed.
• Proposed inspection plans are economical for composite sample testing.
• A case study of milk product lot inspection is given.
• Plans are tabulated for the convenience of practitioners.

Sampling inspection plans for compositional fractions based on the beta distribution are discussed. Design of plans to control the proportion nonconforming levels are covered. It is shown that the traditional plans based on the normal distribution fail to maintain the desired risks. Plans based on the beta distribution are not only suitable for bulk product inspection, but they also achieve considerable economy when composite samples are used in testing.