Grouping Rule

Grouping rules define how samples are combined into subgroups for analysis. Groupings determine the way each data point is displayed on a chart. This table lists the grouping rules that can be used to create different subgroup structures from the same data set:

Grouping	Description
Month	The samples collected in a month are combined and analyzed as a single point on an SPC trend chart.
Week	The group samples collected in the same week are combined and analyzed as a single point on an SPC trend chart.
Day	The group samples collected in a single day are combined and analyzed as a single point on an SPC trend chart.
Shift	The group samples collected during the same shift are combined and analyzed as a single point on an SPC trend chart.
Hour	The group samples collected in the same hour are combined and analyzed as a single point on an SPC trend chart.
MS (Measurement Set)	Groups samples associated with the same inspection measurement set that are collected at the same time are analyzed as a single point on the SPC chart. This grouping method is widely used for analyzes.
MS-H (Measurement Set & Head)	Data from the same inspection measurement set are split into individual data points for each head in the set. This method results in each data point on the chart defining an individual sample. In that case, the SPC Study Type must use the moving average and moving range analysis.
MS-H-S (Measurement Set, Head & Sample)	Data from the same measurement set are split into individual data for each head and sample. This method results in single sample points. In this case, the SPC Study Type must use the moving average and moving range analysis.
MS-H-S-P (Measurement Set, Head, Sample & Position)	Data from the same measurement set are split into individual data for each head, sample, and position. This method results in single sample points. In this case, the SPC Study Type must use the moving average and moving range analysis.