These statements specify directories that will be searched for the programs named in EXEC statements.
To enable JOBLIB/STEPLIB processing do the following:
If the partitioned data set referenced in a particular STEPLIB or JOBLIB statement exists as a catalog entry, the DD is allocated. Where there are multiple partitioned data sets referenced in a STEPLIB or JOBLIB concatenation, only those data sets that exist are mapped as part of the JOBLIB or STEPLIB concatenation.
Any job that has a STEPLIB and/or JOBLIB statement continues to run unmodified.