A system that limits the time data is stored to the future need and capability of the system for viewing it. In the shorter term, that's usually controlled by the audit requirements and statute of limitations. In the long term it's most often mandated by the technology. Upgrades in technology create situations where businesses can have hundreds of 1.5 inch floppy disks in a box, a few 10 megabyte hard drives, reels of backup tapes, a pile of backup CDs, some data DVDs and on and on. If you don't have computers that will read all of that, it's useless. Whether or not it's worth the effort to continually update the data to the current level of technology becomes the controlling factor.
