The organization has to include disaster recovery in their continuity planning. Relevant disasters for the planning are natural disasters (e.g floods, earthquake, hurricanes) and human caused disasters (e.g terror attack, chemical attack/incident, insider attack).
In disaster planning there is greater emphasis on the returning operations to normal levels safely than in continuity planning. After this focus moves to resuming normal operations.
The continuity plans must be updated at least annually or after significant changes.