The authors present a simple-to-use Microsoft Excel-based statistical tool that uses cumulative sum techniques to aid retrospective understanding of data trends. Process variability must be assessed ...

Standard textbooks on statistical process control generally offer simple procedures to construct control charts. In many situations the resulting charts are of limited use because the variance ...

Methods of statistical process control were briefly investigated in the field of educational measurement as early as 1999. However, only the use of a cumulative sum chart was explored. In this article ...

Control charts that are properly constructed and maintained prevent false out-of-control signals and provide a useful method for monitoring a process. Process control is and has been an important ...

The Shewhart chart is named after Walter A. Shewhart (1891-1967), a physicist at the Bell Telephone Laboratories, who introduced the method in 1924 and elaborated upon it in his book Economic Control ...