According to the CISM Review Manual, a business impact analysis (BIA) is the most useful tool when determining the business continuity strategy for a large organization's data center, as it helps to identify and prioritize the critical business processes and resources that depend on the data center, and the impact of their disruption or loss. A BIA also provides the basis for defining the recovery time objectives (RTOs) and recovery point objectives (RPOs) for the data center, which guide the selection of the appropriate business continuity strategy.
References = CISM Review Manual, 27th Edition, Chapter 3, Section 3.5.2, page 1511.