RCHART Statement: SHEWHART Procedure

The RCHART statement creates an chart for subgroup ranges, which is used to analyze the variability of a process.¹

You can use options in the RCHART statement to

• compute control limits from the data based on a multiple of the standard error of the plotted ranges or as probability limits

• tabulate subgroup sample sizes, subgroup ranges, control limits, and other information

• save control limits in an output data set

• save subgroup sample sizes, subgroup means, and subgroup ranges in an output data set

• read preestablished control limits from a data set

• specify the method for estimating the process standard deviation

• specify a known (standard) process standard deviation for computing control limits

• display distinct sets of control limits for data from successive time phases

• add block legends and symbol markers to reveal stratification in process data

• superimpose stars at points to represent related multivariate factors

• clip extreme points to make the chart more readable

• display vertical and horizontal reference lines

• control axis values and labels

• control layout and appearance of the chart

You have three alternatives for producing charts with the RCHART statement:

• ODS Graphics output is produced if ODS Graphics is enabled, for example by specifying the ODS GRAPHICS ON statement prior to the PROC statement.

• Otherwise, traditional graphics are produced by default if SAS/GRAPH^® is licensed.

• Legacy line printer charts are produced when you specify the LINEPRINTER option in the PROC statement.

See Chapter 3, SAS/QC Graphics, for more information about producing these different kinds of graphs.