BS ISO 8423:2008

1   Scope This International Standard specifies sequential sampling plans and procedures for inspection by variables of discrete items. The plans are indexed in terms of producer’s risk point and the consumer’s risk point . Therefore, they are suitable not only for the purposes of acceptance sampling , but for the more general purpose of the testing of simple statistical hypotheses for proportions. The purpose of this International Standard is to provide procedures for the sequential assessment of inspection results that may be used to induce the supplier to supply lots of a quality having a high probability of acceptance. At the same time, the consumer is protected by a prescribed upper limit to the probability of accepting a lot (or process) of poor quality. This International Standard is primarily designed for use under the following conditions:

       a)  where the inspection procedure is to be applied to a continuing series of lots of discrete products all supplied by one producer using one production process. In such a case, sampling of particular lots is equivalent to the sampling of the process. If there are different producers or production processes, this International Standard shall be applied to each one separately; 
   
   
     
       b)  where only a single quality characteristic   x   of these products is taken into consideration, which mus...