SMP/E orders the processing of the set of SYSMODs being applied to ensure proper processing of JCLIN, element selection, and merges of source and macro updates.

The order in which the SYSMODs being applied are processed is determined from the prerequisite (PRE) data supplied on the ++VER statement for the SYSMOD. SYSMODs named as prerequisites are processed before the SYSMODs naming them.

If no prerequisite order can be determined between SYSMODs, function SYSMODs are processed first, followed by service SYSMODs (PTFs, then APARs, then USERMODs).