There is a lot of options in SDSF regarding parallel sysplex (also refered to as //sysplex). The introduction of parallel sysplex also introduced a new parameter on the JOB card in JCL called SCHENV for scheduling environment. SCHENV=MYENV is a kind of /*JOBPARM SYSAFF=MYID where SCHENV is the logical name for one or more MVS systems in the sysplex, while SYSAFF refers to the actual name of the MVS system.

The command SE in SDSF shows you the logical names that you can assign to the parameter SCHENV. At the same time you can see the MVS system(s) assigned to the different SCHENV names. Let's assume that you normally use /*JOBPARM SYSAFF=MVSA because your job is bound to be executed on MVSA. Now you can use SDSF command SE to identify if there is a SCHENV name corresponding to MVSA. Let's assume that there is such a name and the name is JULIUS. Now you can remove your SYSAFF=MVSA from /*JOBPARM and add the parameter SCHENV=JULIUS to the JOB card instead. The result will be exactly the same.

The trick about using SCHENV instead of SYSAFF is that operations can redirect all jobs using SCHENV=JULIUS to another MVS system by giving a simple command to JES "on the fly" compared to the tedious task of changing all the jobs using /*JOBPARM SYSAFF=MVSA to make them run on another MVS system. You must remember to remove your SYSAFF=MVSA from your /*JOBPARM if you want to benefit from using SCHENV instead, because SYSAFF will be used instead of SCHENV if present.