Read my Question here. For your quick reference I have given my question and answer as below.
How to delete an input dataset using IEBGENER utility?
In the input file, you need to give DISP= (OLD,DELETE). For output file, you need to give DD DUMMY.
After executing the JOB with IEBGENER utility, the input file will be deleted successfully.
// DD DSNAME=TEST.INPUT
// DD DUMMY