Substantiation of sequential test parameters for mass-produced electronic devices

A planning methodology is proposed for checking the acceptability of a lot of products in terms of the percentage of defectives using the Sequential Probability Ratio Test (SPRT). For a stable, high-volume production process, in which the statistics is known (from the percentage of defectives in an accepted lot and from rejection of a whole the lot, cost per observation, the apriori probability distribution of the percentage of defectives) the sought test is to be planned, such that the expected loss due to wrong decisions and to the cost of the observations - is minimal (maximum profit). The originality of the proposed approach lies in the fact that the permissible percentage of defectives (e.g. in the form of the commonly used Acceptable Quality Level (AQL) and Limiting Quality Level (LQL)) is not specified. The only relevant information is the statistic data as mentioned above.