LTPD SAMPLE SIZE CALCULATOR

Enter Known Defect Rate in PPM

Enter Confidence Level in Percent (1 to 99)


Establishing Sample Size For Process Validation

By Ashok Kizhepat

Sample size calculator above is a web application developed using the Google Cloud Platform. This app can be used to calculate the LTPD sample size. Just enter the known reject rate in (PPM) and the confidence level in percentage.

Lot Tolerance by Percent Defective (LTPD), Is a sampling plan that specifies the minimum sample size to ensures with 95 percent confidence that a lot having a percent defective equal to the LTPD (Known defect rate) will not be accepted.

The calculation of sample size is based on the consumer's risk. This is the probability that a defective product will be accepted by the customer. Producer's risk is the probability that a good product will be rejected by the customer.

LTPD should be utilized based upon an organizations risk acceptance determination threshold, industry practice, guidance documents, and regulatory requirements. It should be noticed that the lot size does not affect the minimum sampling requirements.

(Note: 95 percent confidence is generally used; however, other confidence levels can and may be appropriately used based on organizational or regulatory need.)