Process control and capability analysis study requirements and dataset layout.
Use a column for each variable (Copper); each row has a single measurement.
Use a column for each variable (Copper), and optionally columns for subgroup (Day), stratification (Operator), phase/stage (Phase); each row has a single measurement.
Use a column for each subgroup (Sample), a column for the subgroup size (Sample size), and a column for the number of cases (Frequency); each row has a the frequency count for each sample.
