Many would argue that a disaster recovery plan should have five phases, which are:

Preparation: The planning and rehearsal necessary to respond to a disaster.

Response: The identification of a disaster, notification of appropriate individuals, and immediate response to the disaster.

Recovery: The recovery of necessary business information and systems

Resumption: The restoration of critical business functions.

Restoration: The re-establishment of operations at the primary site as it was before the disaster.

But this is very generic guidance though it might well form the outline of a good plan. What do you think is the most critical phase in this scheme?