Effective backup of documents is generally more easily achievable once the move has been made from paper to electronic files. A robust electronic backup routine will include daily (or more frequent in some critical real-time businesses) saving of data to storage media separate from the business' operational system.
Don't forget that a copy of this must be stored offsite in case of physical destruction of, or theft from the main site, and the offsite copy must be refreshed regularly.
One other trap to avoid: the situation where a system is being restored from the backup media, and a fault in the system that caused the initial problem corrupts the backup copy. So the backup must either be duplicated or incapable of being overwritten.
Remember that daily backup will faithfully copy the latest state of the system. If someone inadvertently or otherwise deletes valuable data (such as the Customer Information System) and the system is backed up before this problem comes to light, the new backup is of no value in solving this problem. The key issue is that earlier copies of the backups must be kept available. Most businesses now keep the daily backups for the preceding week or fortnight. In addition, it is prudent to retain the backups from the preceding key dates in the business calendar: probably year-end, and quarterly accounting dates. This takes us across the boundary from backup (essentially a short-term routine) to archiving, which is the longer term record keeping.