STEPLIB

The STEPLIB DD statement defines a private library that the system makes available to a job step. MVS searches this library before it searches the system libraries for the program named in the PGM= field of the EXEC statement.

Hints

If there is excessive I/O to STEPLIB in an IMS environment, a preload list can reduce some of the I/O. You need the modules that are being loaded by MVS to build this preload list.

Check the STEPLIB concatenation to ensure that the data sets accessed most frequently are placed at the beginning of the concatenation. Refer to the Data Set Characteristics report to see which data sets are accessed most frequently.