XRCHART Statement: SHEWHART Procedure

Saving Summary Statistics

Note: See Mean and Range (X-Bar and R) Charts in the SAS/QC Sample Library.

In this example, the XRCHART statement is used to create a summary data set that can be read later by the SHEWHART procedure (as in the preceding example). The following statements read measurements from the data set Wafers and create a summary data set named Waferhist:

proc shewhart data=Wafers;
   xrchart Diameter*Batch / outhistory = Waferhist
                            nochart;
run;

The OUTHISTORY= option names the output data set, and the NOCHART option suppresses the display of charts. FigureĀ 17.109 contains a partial listing of Waferhist.

Figure 17.109: Partial Listing of the Summary Data Set Waferhist

Summary Data Set for Wafer Diameters

Batch DiameterX DiameterR DiameterN
1 34.992 0.02 5
2 34.994 0.03 5
3 34.998 0.01 5
4 34.998 0.02 5
5 34.992 0.02 5



There are four variables in the data set Waferhist:

  • Batch contains the subgroup index.

  • DiameterX contains the subgroup means.

  • DiameterR contains the subgroup ranges.

  • DiameterN contains the subgroup sample sizes.

Note that the summary statistic variables are named by adding the suffix characters X, R, and N to the process Diameter specified in the XRCHART statement. In other words, the variable naming convention for OUTHISTORY= data sets is the same as that for HISTORY= data sets.

For more information, see OUTHISTORY= Data Set.