The 7 Rs of Migration Strategy
Apply Rehost, Replatform, Repurchase, Refactor, Retire, Retain, and Relocate to categorise each workload and build a migration plan.
Why Migration Strategy Matters
Moving workloads to AWS is rarely a single action — it is a portfolio of decisions made for each application. The 7 Rs of migration give architects a common vocabulary to classify applications and choose the right migration path. For the SAA-C03 exam, you must know which R applies to a given scenario description, as questions often test your ability to match an application characteristic to the correct migration strategy.
Rehost: Lift and Shift
Rehost (Lift-and-Shift) moves an application to AWS with no changes to the application code or architecture. Use AWS Application Migration Service (MGN) to replicate on-premises VMs to EC2 instances. Rehost is fastest to execute and carries the least risk, making it ideal for large-scale migrations where speed matters and optimisation can happen later. It does not take advantage of cloud-native features.
# Rehost signal words in exam questions:
# 'move quickly', 'minimal changes', 'same OS and application',
# 'lift-and-shift', 'fastest migration'
# --> Answer: AWS Application Migration Service (MGN)