Many a times, when we are making changes to an element (COBOL program, JCL, PROC), we open it in VIEW mode and make changes. Then we come out by mistake and lose all changes.
Also it is safe side to open element in VIEW mode and confirm all the changes are fine and then save it.
This tool helps you in doing that. You can save an element that you have made changes in the VIEW mode by using this tool FSAVE.
Once you have copied this tool into the PDS that have your REXX execs (in SYSEXEC or SYSPROC), you can just type in FSAVE in the command line and it saves the PDS member that you have edited in VIEW mode.
Please see below link to know how to setup your REXX PDS