Summary Statistics for Subgroups and Groups

Quality AnalytiX provides several types of calculations for both subgroups and groups. You can set these calculations while configuring an SPC tag and view values from these calculations within both TrendWorX64 plots and ReportWorX forms.

Statistics for Subgroups

Within subgroups, you can view the following summary calculations:

X-Bar: Computes the average value of the samples in the subgroup.
Range: Computes the difference between the highest and lowest values of the samples in the subgroup.
Median: Computes the sample value that falls in the middle of the subgroup when the values are arranged in numerical order.
S: Computes the standard deviation of the samples in the subgroup.
Moving Average: Computes the average value of the most recent samples within the subgroup.
Moving Range: Computes the difference between the highest and lowest values of the most recent samples within the subgroup.
Cusum: Computes the cumulative sum of the sample values in the subgroup.

Statistics for Groups

Within groups, you can view the following summary calculations:

CL: Displays the center line for the group (constant value).
UCL: Displays the upper control limit for the group (constant value).
LCL: Displays the lower control limit for the group (constant value).
X-Double Bar: Computes the average value of the subgroups in the group (the "average of averages" of the original samples).
Average Range: Computes the average value of the range among the subgroups in the group.
Sbar Range: Computes the difference between the highest and lowest standard deviation values among the subgroups in the group.
Grand Moving Average: Computes the average value of the most recent samples within the subgroups in the group (the "average of moving averages" of recent samples).
Average Moving Range: Computes the average value of the subgroups' moving ranges.
EWMA: Computes the exponential weighted moving average of the most recent subgroups in the group. More recent samples in the subgroups of the group receive more weight, and older samples receive progressively less weight (following an exponential decay curve).