Suppose that, some time ago, you created CICS® System Definitions in CICS PA using version-specific data set names for the MCT and SDFHLOAD libraries. Now you want to upgrade your CICS System Definitions in CICS PA to match this change in your system environment. Rather than selecting and then editing each system definition individually, you can upgrade several (or all of them) together.
For details, see Mass Update of Personal CICS System Definitions.