• The IEFBR14 is a no-operation or dummy utility supplied by IBM.
• In the utility name, "IEB" means it is a data set utility program, and "BR14" means "branch to register 14".
• During the IEFBR14 execution, it branches to the address in Register 14, which returns the control to the operating system. The Assembler instruction for this process is BR 14. That's how this utility got its name IEFBR14.
• IEFBR14 uses the DISP parameter to process DD statements specified along with the EXEC statement by returning the control to z/OS.
• Submitting a JCL to run IEFBR14 causes the z/OS job scheduler to check JCL statements for syntax errors.

Tasks -

• IEFBR14 utility perform the following tasks -
  • Allocate/create datasets
  • Delete datasets
  • Uncatlog Datasets
  • Catalog Datasets
  • Setting return code to zero

Advantages -

• Creating/deleting data sets.
• Catalog/uncatalog the data sets.
• Used for Syntax Checking.
• Used to SET the return code to Zero.
• In most of the scenarios, it is used in the first step to delete the output data sets in the scheduled JOB to run multiple times with the same output data set names.
• Replacing the original program name with IEFBR14 and submitting it completes the syntax checking.

Disadvantages -

• Can't open the data sets.
• It is not recommended for allocating multi-volume data sets.