All Shewhart charts have the following characteristics: Each point represents a summary statistic computed from a sample of measurements of a quality characteristic. For example, the summary statistic ...

Part 1 of this article series demonstrates, using real-world process data, that the four fundamental assumptions underlying the classical Shewhart control charts—randomness, independence, constant ...

Although cusum charts and Shewhart charts are both used to detect shifts in the process mean, there are important differences in the two methods. Each point on a Shewhart chart is based on information ...

Statistical process control (SPC) involves ongoing checks to ensure that neither the mean nor the variability of the process readings has changed. Conventionally, this is done by pairs of ...

This is a preview. Log in through your library . Abstract Traditional statistical process control charts assume that observations are independent and normally distributed about some mean. We ...