Inspection Level
Meaning ~ The statistical parameter in acceptance sampling that dictates the sample size of a batch of goods based on the total lot quantity and chosen severity.
Attribute Testing
Meaning
Industrial inspection protocols classify manufactured items based on a simple binary pass or fail assessment. This method, known as attribute testing, evaluates products against specific qualitative thresholds rather than measuring their exact dimensions. Quality control teams use this approach to check for visible surface defects, missing components, or functional failures.
Pass Fail Assessment
Operational efficiency increases when inspectors do not have to record precise analog measurements for every sample. During attribute testing, a part is accepted if it fits a go gauge or rejected if it does not. This rapid evaluation keeps the inspection line moving without sacrificing consistency.
Sample Size
Statistical sampling plans require larger specimen groups for qualitative checks than for variable checks. Because attribute testing does not capture the degree of variation, more units must be analyzed to establish statistical confidence. The sample size is usually determined by standard tables like ansi asq z1.4.
Rejection Threshold
Contracts must define the exact number of failing units that will trigger a batch rejection. When attribute testing reveals a non-conformance rate above the acceptable quality limit, the entire shipment is locked in quarantine. Buyers use these thresholds to negotiate pricing discounts or force the factory to perform a complete manual sort at their own expense.
Neglecting to define these limits in the purchase order can leave the importing company with thousands of unsellable goods and no legal recourse.