In some cases,the xbar-chart is used without the R-chart because the within sample variation is not of concern.

Question

Quizplus · Accepted Answer

The xbar-chart is used to monitor the central tendency of a process, while the R-chart is used to monitor the variability within each sample. If the within sample variation is not of concern or can be assumed to be negligible, then the R-chart may not be necessary and the xbar-chart can be used alone to monitor the process.

In Some Cases,the Xbar-Chart Is Used Without the R-Chart Because