engleski

Studying an OC Curve of an Acceptance Sampling Plan: A Statistical Quality Control Tool

The research problems under consideration are relationships between sampling risks and other elements inbuilt in a single acceptance sampling plan. Two levels of quality are considered: first, average quality level desired by the consumer AQL, and, second, quality level called lot tolerance percent defective LTPD, or the worst level of quality that the consumer may tolerate. The producer’ s risk is the risk of incorrect rejection is the risk that the sampling plan will fail to verify an acceptable lot’ s quality set by AQL and, thus, reject it. The probability of acceptance a lot with LTPD quality is the consumer’ s risk or the risk of incorrect accepting. Operating characteristic (OC) curve describes how well an acceptance plan discriminates between good and bad lots. Acceptance sampling plan consists of a sample size n, and the maximum number of defective items that can be found in the sample c. The OC curve pertains to a specific plan, i.e. to a combination of the sample size n and the acceptance criterion or level c. Using ExcelOM2 software, the following findings were found: (1) with c, AQL and LTPD fixed, the increasing sample size n resulted with the risk increased and the risk decreased ; and (2) with n, AQL and LTPD fixed, the increasing critical value c implicated that the risk decreased, but the risk increased ; (3) if AQL is increased, with all other components n, c, and LTPD fixed, then producer’ s risk would increase, but consumer’ s risk would remain the same ; and, (4) if LTPD is increased, with all other components n, c and AQL fixed, would remain the same, while would decrease. In this paper some previous research results from studying risk and risk in audit sampling based on acceptance sampling applications from [1] are shortly presented.

Statistical quality control; decision making; acceptance sampling plan; consumer’ s risk; producer’ s risk; acceptable quality level; lot tolerance percent defective.

ISBN 960-8457-46-7. Citirano u: INSPEC Science Abstracts series, CSA- Cambridge Scientific Abstract.