Title: When Should the Limits on a Shewhart Control Chart Be Other Than a Center Line ±3 Sigma?
Author: Lloyd S. Nelson
Publication Source: Journal of Quality Technology, Vol. 35, No. 4, October 2003, pp. 424-425
Abstract
This technical aid addresses the traditional use of 3 standard deviation limits on control charts, and addresses the "Type I" and "Type II" errors that may be encountered.
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