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 ...

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 ...