Major Defect
Meaning ~ A quality control category for product deviations that impair functionality or reduce commercial value without introducing safety or regulatory risks.
Normal Inspection Level
Meaning
Baseline sampling intensity settings in acceptance sampling plans define the standard sample size drawn during routine quality control audits. International standards like ISO 2859-1 establish default testing levels for suppliers with stable quality histories. Operating under a normal inspection level balances inspection costs against consumer risk during steady-state production runs.
The baseline setting transitions to tightened or reduced inspection levels when historical quality performance crosses predefined statistical thresholds.
Sampling Baseline
Default inspection tables determine the exact number of units to sample based on total lot size and general inspection level parameters. Standard sampling balances defect detection sensitivity against factory floor inspection labor costs.
Switching Rule
Standardized switching rules dictate when quality teams must escalate or de-escalate sampling intensity based on consecutive lot results. When two out of five consecutive lots fail initial testing, quality managers step up from a normal inspection level to a tightened inspection regime with larger sample sizes. Conversely, five consecutive accepted lots allow transition to reduced inspection intensity, lowering sample counts and inspection costs.
Maintaining clear switching rules prevents arbitrary adjustments to sample sizes by inspection personnel.
Cost Balance
Routine baseline sampling optimizes quality assurance expenses while maintaining statistically sound protection against non-conforming batches. Procurement contracts specify baseline inspection levels to establish clear pre-shipment testing costs and timelines for both buyer and supplier.