Gartner, a highly influential information technology research company, describes 5 options for organizations migrating to the cloud. These cloud migration strategies are commonly known as the “5 R’s”:
Rehost - Rehosting can be thought of as “the same thing, but on cloud servers”. Companies that choose this strategy will select an IaaS (Infrastructure-as-a-Service) provider and recreate their application architecture on that infrastructure.
Refactor - Companies that choose to refactor will reuse already existing code and frameworks, but run their applications on a PaaS (Platform-as-a-Service) provider’s platform – instead of on IaaS, as in rehosting.
Revise - This strategy involves partially rewriting or expanding the code base, then deploying it by either rehosting or refactoring (see above).
Rebuild - To “rebuild” means rewriting and re-architecting the application from the ground up on a PaaS provider’s platform. This can be a labor intensive process, but it also enables developers to take advantage of modern features from PaaS vendors.
Replace - Businesses can also opt to discard their old applications altogether and switch to already-built SaaS (Software-as-a-Service) applications from third-party vendors.