Customizing an element—the USERMOD SYSMOD

If you had a requirement for a product to perform differently from the way it was designed, you might want to customize that element of your system. IBM® provides you with certain modules that allow you to tailor IBM code to meet your specific needs. After making the desired changes, you add these modules to your system by installing a USERMOD SYSMOD. This SYSMOD can be used to replace or update an element, or to introduce a totally new user-written element into the system. In either case, the USERMOD SYSMOD is built by you either to change IBM code or to add your own code to the system.

In Figure 1, MOD3 was updated through the installation of a USERMOD SYSMOD.

Figure 1. Customizing an element

Here is an example of a simple USERMOD SYSMOD:

   ++USERMOD(USRMOD1)             /* SYSMOD type and identifier.   */.
   ++VER(Z038) FMID(FUN0001)      /* Apply to this product         */
               PRE(UZ00004)       /* at this service level.        */.
   ++SRCUPD(JESMOD3)              /* Update this source module     */
               DISTLIB(AOSFB)     /* in this distribution library. */.
   ...
   ... update control statements
   ...

Prerequisites for USERMOD SYSMODs are the installation of a function SYSMOD, and possibly the installation of other PTF, APAR, or USERMOD SYSMODs.