Two key factors to consider when determining priorities are Recovery Point Objective (RPO) and Recovery Time Objective (RTO). RPO defines the amount of data, in time, which your business can afford to lose for a particular system.
For some applications, recovering data from yesterday or even last week may be ok - in this case, the RPO would be days or weeks. Other applications and data, for which any loss is not acceptable, you may choose to have a RPO of minutes or less.
While RPO defines how much data is protected, RTO defines how long it takes to recover that data. RTO is the amount of time the application can be down and not available to users or customers. Can your business survive without a particular application for a few minutes? How about a few days?
These factors will help to set appropriate priorities for recovering systems and data and determine the right solution for each. Do not assume that your tape backups are sufficient.They are not likely suitable for meeting the RPO and RTO of all of your systems.
With tape, the recovery point is back to the time of the last backup - typically a day or more. Recovery Time with tape is generally a day at best because tapes must be retrieved and the data must be restored from them.
For most businesses,these are not acceptable levels for all of systems.