In supplement Chapter 10 entitled 'Acceptance sampling' the author reviews the purpose acceptance sampling and contrasts it with process control. The chapter also compares and contrasts single and multiple sampling plans and discusses the concept of average outgoing quality level. | Acceptance Sampling McGraw-Hill/Irwin Copyright © 2012 by The McGraw-Hill Companies, Inc. All rights reserved. You should be able to: Explain the purpose of acceptance sampling Contrast acceptance sampling and process control Compare and contrast single- and multiple-sampling plans Determine the average outgoing quality of inspected lots 10S- Student Slides Acceptance sampling A form of inspection applied to lots or batches of items before or after a process, to judge conformance with predetermined standards May be applied to both attribute and variable inspection 10S- Student Slides Acceptance sampling is most useful when at least one of the following conditions exists: A large number of items must be processed in a short time The cost consequences of passing defectives are low Destruction testing is required Fatigue or boredom caused by inspecting large numbers of items leads to inspection errors Student Slides 10S- Sampling plans: Plans that specify lot size, sample . | Acceptance Sampling McGraw-Hill/Irwin Copyright © 2012 by The McGraw-Hill Companies, Inc. All rights reserved. You should be able to: Explain the purpose of acceptance sampling Contrast acceptance sampling and process control Compare and contrast single- and multiple-sampling plans Determine the average outgoing quality of inspected lots 10S- Student Slides Acceptance sampling A form of inspection applied to lots or batches of items before or after a process, to judge conformance with predetermined standards May be applied to both attribute and variable inspection 10S- Student Slides Acceptance sampling is most useful when at least one of the following conditions exists: A large number of items must be processed in a short time The cost consequences of passing defectives are low Destruction testing is required Fatigue or boredom caused by inspecting large numbers of items leads to inspection errors Student Slides 10S- Sampling plans: Plans that specify lot size, sample size, number of samples, and acceptance/rejection criteria Single-sampling plan Double-sampling plan Multiple-sampling plan Student Slides 10S- Single-sampling plan One random sample is drawn from each lot Every item in the sample is inspected and classified as “good” or “defective” If any sample contains more than a specified number of defectives, c, the lot is rejected Student Slides 10S- Double-Sampling Plan Allows the opportunity to take a second sample if the results of the initial sample are inconclusive Two values are specified for the number of defective items A lower level, c1 An upper level, c2 If the number of defectives in the first sample is ≤ c1 the lot is accepted and sampling is terminated > c2 the lot is rejected and sampling is terminated Between c1 and c2 a second sample is collected The number of defectives in both samples is compared to a third value, c3 If the combined number of defectives does not exceed this value, the lot is accepted; otherwise, it is .
