Whether your 3000 environment is in transition, or you're staying in the familiar fields to homestead, you will have versions. Any large entity like an application goes through changes. You'll want to track yours with a Version Control System (VCS).
Several are available today for the 3000 community, including one from HP you might still be able to purchase. (After all, software subsystem sales were supposed to go on through the end of HP's support.)
Walter J. Murray, formerly of HP's labs and now working in the IT group at the California Department of Corrections and Rehabilitation, says, "I heartily recommend HP SRC (Software Revision Controller). We have been using it extensively for about three years. We are a COBOL and PowerHouse 4GL shop, but we use HP SRC for just about every kind of file except TurboIMAGE databases. Contact me if you'd like more information."
Non-HP VCS solutions include the open source CVS (Concurrent Version System) suite, which HP and Interex used as a method of HP's Shared Source project to put parts of MPE/iX source into the user community.
Pete Eggers added, "If your developers use PCs to edit and write COBOL, then set up a Linux server with either Subversion (sort of a next-generation CVS), or Git, if you are definitely more geek-oriented. Both are being actively used and developed all over the world, and have more capabilities and features than you are ever likely to use. There are also a variety of add-ons to both, including GUI front-ends, including the old warhorse CVS."