This methodology requires the most effort to implement but it results in the most optimised recurring cost and will provide the best scalability for apps. This involves re-adapting the code of applications and the heavy use of SAAS solutions in order to replace existing hosted applications.
This method utilizes the power of PAAS services, like transferring a database to an as-a-service model, the use of containers for some apps or the use of network/security functions as a service. Greater scalability and lower cost of operation is achieved.
the migration of workloads from to the cloud without changing the architecture. Machines get to keep their OS and apps. This is the quickest and easy way to migrate, but since its utilising IAAS, its is also the most expensive on the long term.