Histograms are typically used in process capability analysis to compare the distribution of measurements from an in-control process with its specification limits. In addition to creating histograms, you can use the HISTOGRAM statement to do the following:

• specify the midpoints or endpoints for histogram intervals

• display specification limits on histograms

• display density curves for fitted theoretical distributions (beta, exponential, gamma, Johnson , Johnson , lognormal, normal, and Weibull) on histograms

• request goodness-of-fit tests for fitted distributions

• display kernel density estimates on histograms

• inset summary statistics and process capability indices on histograms

• save histogram intervals and parameters of fitted distributions in output data sets

• create hanging histograms

• request graphical enhancements

• create comparative histograms by using the HISTOGRAM statement together with a CLASS statement

You have three alternatives for producing histograms with the HISTOGRAM statement:

• Traditional graphics are produced by default.

• ODS Graphics output is produced when you specify the ODS GRAPHICS statement prior to the PROC CAPABILITY statement.

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

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