As installation requirements change, it might be necessary to update definitions of the storage classes, management classes, storage groups, data class, and ACS routines. You can modify definitions for these constructs using the ISMF ALTER panels for all OAM object environments.
Perform these updates with caution because objects that do not require processing after the definition is changed are not affected by the change, even though they are assigned to the class to which the new definition applies. The updated definitions are used only for objects entering the system, or processed by the system, after the change. This situation is particularly true in changes to management class definitions that affect retention, backup, or class transition.