Return code simulation logic

The Step Restart of a job is performed by return code simulation. The Scheduler obtains a history of the previous runs, the step execution, and the return codes from the Operinfo record. Then it adds a pre-step named EQQCLEAN to the JCL. The list of simulated steps and return codes serves as input for EQQCLEAN.

At run time, EQQCLEAN checks the JES control blocks and alters them to force the simulated return codes so that IF THEN ELSE and COND can follow the correct logic.

Abended steps are simulated as flushed for the following reasons:
  • IF THEN ELSE or COND related to abended steps are supposed to be run immediately at abend time. The flushed simulation avoids the duplicate execution of these steps.
  • If the abended steps were not simulated as flushed, JES would flush all the steps following the abended steps again.