A Criterion to Limit Inspection Effort in Continuous Sampling Plans

1.1 Continuous Sampling Plans The CSP-1 continuous sampling plans introduced by H. F. Dodge 1 are designed for continuous or "belt" production of discrete units of product. To apply such a plan, inspected units must be classified as either "defective" or "nondefective". The inspector begins by inspecting each unit made in succession until a specified number, i, of consecutive units are found nondefective. A sequence of units so inspected is called a screening sequence and the number i the clearing number. After the initial screening sequence has ended, the inspector samples a fraction / of the units presented to him. He continues to sample until he finds a defective unit. At this point he again resorts to screening, following the same procedure as before, so that he alternates between screening and sampling inspection. The inspector rejects (or sets aside for correction) any inspected unit found to be defective and accepts all others. Two refinements of this plan, CSP-2 and CSP-3, have appeared 2 as well as generalizations of CSP-1 3 ' 4 ' 5 entailing two or more levels of sampling inspection. In addition, various sequential continuous inspection plans have been proposed. 6 115