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Carl Berardinelli

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Short-Run Statistical Process Control Techniques

Short production runs are a necessity in high-mix, low-volume manufacturing environments. The trend in manufacturing has been toward smaller production runs, with production runs – as well as products – tailored to the individual customer’s needs. Although this minimizes inventory and improves responsiveness to the customer, it complicates the application of statistical process control (SPC). Classical…


Using Control Charts or Pre-control Charts

Every process falls into one of four states: Ideal: produces 100 percent conformance and is predictable Threshold: predictable but produces the occasional defect Brink of chaos: not predictable and does not produce defects Chaos: not predictable and produces defects at an unacceptable rate Processes tend to migrate toward chaos if not effectively managed. Pre-control Charts…


Multivariate Control Charts: T2 and Generalized Variance

Multivariate analysis techniques may be useful in statistical process control (SPC) whenever there is more than one process variable. Multivariate control charting is usually helpful when the effect of multiple parameters is not independent or when some parameters are correlated. This article focuses on parameters that correlate when the Pearson correlation coefficient is greater than…


The Complete Guide to Understanding Control Charts

Control charts have two general uses in an improvement project. The most common application is as a tool to monitor process stability and control. A less common, although some might argue more powerful, use of control charts is as an analysis tool. The descriptions below provide an overview of the different types of control charts…


Ron Santo, Baseball’s Hall and a Lesson in Desirability

Based on the desirability function, using batting average, home runs, runs batted in (RBIs), All Star Game appearances and Gold Glove awards all weighted equally, Ron Santo, a third baseman for the Chicago Cubs from 1960 to 1973, should be a member of the National Baseball Hall of Fame. An understanding of the desirability function…