In this article, the author investigates the use of the Cumulative Sum (CUSUM) chart, which is a useful tool to detect small changes in a process. This paper makes use of a Minitab macro which may be downloaded from the Macro Catalog. Keith M. Bower, EXTRAOrdinary Sense, May 2001
Addresses Gage Repeatability and Reproducibility (Gage R&R) using the functionality in Minitab Release 13.3. After discussing some theory behind the ANOVA output, the associated results from an example are analyzed and conclusions drawn from a practical perspective, referencing several industry-wide guidelines. Keith M. Bower and Michelle E. Touchton, Asia Pacific Process Engineer, April 2001
Two-part article: This part addresses capability analysis when one is dealing with a process which may not be adequately modeled by a Normal distribution. He discusses data transformations using the Box-Cox technique, as well as the fitting of a Weibull distribution. The paper also includes a methodology for choosing between the two techniques in practice, based on probability plots and the Anderson-Darling statistic. Keith M. Bower, EXTRAOrdinary Sense, March 2001
Addresses the paired t-test procedure, to be used when some dependency exists between two populations. This is illustrated by an experiment involving measurements of tire wear using two distinct methods (hence each tire in the study meets both measurement methods.) Assumptions, results, and the conclusions from this actual study are illustrated using Minitab output. Keith M. Bower, Scientific Computing & Instrumentation, February 2001
Two-part article: This part addresses the assumptions and interpretation of capability analyses, including Cp, Cpk as well as "Sigma" values. In this paper, the assumption of Normality is valid for the example under discussion. Keith M. Bower, EXTRAOrdinary Sense, January 2001
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