Acceptance Sampling: AQL, LTPD and Risk
A sampling plan is defined by sample size n and acceptance number c. Its operating-characteristic curve shows the probability of accepting lots at different defect rates. AQL and LTPD are design points on that curve.
Technical publication review required before indexing · Draft reviewed 13 August 2026
Engineering workflow
- Define producer and consumer protection explicitly.
- Form lots consistently and sample randomly.
- Use the controlled standard when claiming ISO 2859-1 or ANSI/ASQ Z1.4 compliance.
- Apply switching and inspection rules where required.
- Keep acceptance sampling separate from process control.
Worked example
A plan may be required to accept a 1% defective lot at least 95% of the time while accepting a 5% defective lot no more than 10% of the time. The calculator searches n and c that satisfy both binomial conditions.
Design a binomial sampling planLimitations and checks
- AQL is not a guaranteed maximum defect level in every accepted lot.
- Finite-lot and hypergeometric effects are not included in the simplified tool.
Relevant AccuTouch next step
Use the calculation as a screening input, then confirm the actual gauge, fixture, software or automation configuration.
Discuss an inspection workflow