ISO 2859-4-2020 pdf download

ISO 2859-4-2020 pdf download.Sampling procedures for inspection by attributes – Part 4: Procedures for assessment of declared quality levels. The audit population is considered as conforming If the population quality indicator (percentage of nonconforming units, or percentage of nonconformities per item, respectively) is smaller or equal to the DQL. Otherwise, the audit population is considered as nonconforming. The inspection objective shall decide on the conformance of the population by taking one of two mutually exclusive decisions: i) rejection, i.e., contradict the quality declaration expressed by the DQL and classify the population as nonconforming; ii) non-rejection or acceptance, i.e., do not contradict the quality declaration expressed by the DQL and classify the population as conforming. 4.4 Decision by sampling Each of the n items in the sample shall he inspected, and the total number d of nonconforming items or, respectively, of the nonconformities on items in the sample shall be determined. — If d is less than or equal to the non-rejection number c, the decision is non-rejection, i.e., the declared quality level is not contradicted. — If d exceeds the non-rejection number c, the decision is rejection, i.e., the declared quality level is contradicted. EXAM PIE Assume that, in the situation considered by the Example in 4J., two or fewer nonconforming items are found in the sample of 127 items. Then the sample result does not contradict the DQL of 0,65% nonconforming items. If three or more nonconforming items are found, the sample evidence contradicts the DQL. 4.5 Disposition of nonconforming items Any nonconforming items or items exhibiting nonconformities found in the sample shall not be returned to the rest of the items unless the nonconforming items are brought to a conforming condition and applicable administrative rules are followed. Examples for the use of the sampling and decision procedure in industrial practice are provided in Annex A. 5 PrInciples Any assessment procedure based on sampling is subject to sampling risk, i.e., the risk of taking an erroneous decision due to the limited information conveyed by a sample. In the present context, there are two types of erroneous conclusions on an audit population: a) rejection although the population is actually conforming, i.e., the population quality indicator (percentage of nonconforming units, or percentage of nonconformities per item, respectively) is actually smaller or equal to the DQL; b) non-rejection although the population is actually nonconforming, i.e., the population quality indicator (percentage of nonconforming...