You can use the GSFMODE=
graphics option to replace an existing graphics output file with a
new graph. To replace an existing graphics output file, the GSFMODE=
option must be set to REPLACE, which is the default value for this
option. When you run a SAS program that creates a graphics output
file and the graphics option GSFMODE=REPLACE is used, the existing
graphics output file is replaced with the new graph. However, a unique
GRSEG is still generated each time you run the procedure.