An important message has to be delivered to VM user USER1.

JOB1 is defined in Control‑M as a cyclic job, with an interval of 20 minutes. JOB1 is triggered by prerequisite condition SHOUT-REQUIRED. The JCL for JOB1 is as follows:

    //JOB1     JOB  ....

    //REQUEST  EXEC PGM=IEBGENER

    //SYSPRINT DD   SYSOUT=*

    //SYSIN    DD   DUMMY

    //SYSUT2   DD   SYSOUT=A,DEST=(VMPROD,IOAVAUTO)

    //SYSUT1   DD  DATA,DLM=@@

    /* REXX EXEC */

    'MSG USER1 Production Job PRDUPDT has abended!'

    IF RC = 0 THEN 'EXEC IOAVCND DELETE SHOUT-REQUIRED 0101'

    EXIT(0)

    @@

    //

JOB1 is submitted by Control‑M upon the creation of prerequisite condition SHOUT-REQUIRED (by another job or process). JOB1 runs under MVS and produces a SYSOUT file containing four REXX statements to be passed to the VM IOAVAUTO machine.

The IOAVAUTO machine reads the file from its reader and processes the command file.

If the MSG command is performed successfully by the IOAVAUTO machine, a job is sent to MVS that deletes prerequisite condition SHOUT-REQUIRED.

If the MSG command is unsuccessful, no feedback is sent back to MVS. As a result, JOB1 is run again by Control‑M (about 20 minutes after its previous run), and another attempt is made to deliver SHOUT message to the VM user.