The PARETO Procedure

Note: See Highlighting the "Vital Few" in the SAS/QC Sample Library.

This example is a continuation of Example 15.2.

In some applications you might want to use colors and patterns to highlight the bars that correspond to the most frequently occurring categories, which are referred to as the "vital few."

The following statements highlight the two most frequently occurring categories in each cell of the comparative Pareto chart shown in Output 15.2.4:

title 'Which Problems Occur Most Often?';
proc pareto data=Failure4;
   vbar Cause / class       = ( Process Day )
                freq        = Counts
                nrows       = 2
                ncols       = 5
                last        = 'Miscellaneous'
                scale       = count
                chigh(2)
                hlleglabel  = 'Severity:'
                catleglabel = 'Failure Causes:'
                odstitle    = title
                nocatlabel
                nocurve
                nlegend;
run;

Specifying CHIGH (2) causes the two highest bars in each cell to be filled with a contrasting color from the ODS style. The new chart is displayed in Output 15.3.1. In all but two of the cells, the two vital problems are Contamination and Oxide Defect.

You can also highlight the "trivial many" categories (also referred to as the "useful many") with the CLOW(m) option. You can use these options in conjunction with the CHIGH(n) and BARS= options. For more information, see the entries for these options in the Dictionary of HBAR and VBAR Statement Options.