The most important factor when designing security controls for new cloud-based services is to understand the business and IT strategy for moving resources to the cloud. This will help to align the security controls with the business objectives, requirements, and risks, and to select the appropriate cloud service delivery and deployment models. The security controls should also be based on the shared responsibility model, which defines the roles and responsibilities of the cloud service provider and the cloud customer in ensuring the security of the cloud environment. Evaluating different types of deployment models, defining an incident response policy, and performing a business impact analysis are also important activities, but they should be done after understanding the business and IT strategy.
Reference = CISM Review Manual, 16th Edition eBook1, Chapter 3: Information Security Program Development and Management, Section: Information Security Program Management, Subsection: Cloud Computing, Page 141-142.