Moving applications to Amazon Web Services can cut infrastructure costs, improve reliability and make it easier to scale, but only if each workload is migrated in the right way. AWS describes seven migration strategies, known as the 7 Rs. This guide explains each strategy with examples, compares them side by side, and shows how to choose the right approach for every application in your portfolio.
The 7 Rs of AWS migration
1. Retire
Switch off applications that are no longer needed. Discovery often reveals duplicate, unused or low-value systems, and retiring them reduces migration effort and cost immediately.
2. Retain
Keep some applications where they are for now, for example systems that were recently upgraded, have strict data residency requirements, or will be replaced soon. Revisit them later.
3. Rehost (“lift and shift”)
Move applications to Amazon EC2 with minimal or no changes, typically using AWS Application Migration Service. It is the fastest way to exit a data centre or old hosting provider, and you can optimise afterwards.
4. Relocate
Move infrastructure to AWS without buying new hardware or rewriting applications, for example moving VMware workloads to VMware Cloud on AWS or moving containers between Kubernetes clusters.
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5. Repurchase (“drop and shop”)
Replace an application with a software-as-a-service product, such as moving from a self-hosted CRM or email system to a SaaS alternative.
6. Replatform (“lift, tinker and shift”)
Make a few targeted changes to benefit from managed services without changing the core architecture, for example moving a self-managed MySQL database to Amazon RDS or Aurora, or running an application on Elastic Beanstalk or containers.
7. Refactor (re-architect)
Redesign the application to be cloud-native, using serverless (AWS Lambda), containers (Amazon ECS or EKS), managed messaging and modern data services. It takes the most effort but offers the biggest gains in scalability, resilience and long-term cost.
Comparing the 7 AWS migration strategies
| Strategy | Effort | Speed | Cloud benefits | Typical use |
|---|---|---|---|---|
| Retire | Very low | Immediate | Removes cost | Unused or duplicate apps |
| Retain | None now | — | None yet | Recently upgraded or constrained apps |
| Rehost | Low | Fast | Moderate | Data centre exit, tight deadlines |
| Relocate | Low | Fast | Moderate | VMware or container platforms |
| Repurchase | Medium | Medium | High (SaaS) | Commodity software such as CRM or email |
| Replatform | Medium | Medium | High | Databases and app servers to managed services |
| Refactor | High | Slow | Very high | Core, growing, business-critical apps |
How to choose an AWS migration strategy
Assess each application against these questions:
- Business value: is the application core to your business and growing, or stable and secondary?
- Technical condition: is the code maintainable, or is it outdated and hard to change?
- Deadlines: do you need to leave a data centre or hosting contract by a fixed date?
- Skills: does your team have cloud-native experience for refactoring?
- Cost: what are current running costs, and what will each option cost to migrate and operate?
- Compliance: are there data residency, security or audit requirements?
A common pattern is to rehost or replatform first to meet deadlines, then refactor the applications that matter most once they are running on AWS.
The AWS migration process
- Assess: inventory applications, servers and dependencies; estimate costs with tools such as AWS Migration Evaluator; build the business case.
- Mobilise: set up a secure AWS landing zone (accounts, networking, identity, logging), choose a strategy per application and plan migration waves.
- Migrate and modernise: migrate in waves using AWS Application Migration Service for servers, AWS Database Migration Service for databases and AWS DataSync for files; test, cut over and decommission old systems.
- Operate and optimise: monitor performance and cost, right-size resources, use savings plans and continue modernising.
Tips for a smooth migration
- Map dependencies first so applications that talk to each other move together.
- Start with a low-risk pilot to prove the process.
- Plan cut-overs with data synchronisation and a rollback option to minimise downtime.
- Set up security and cost guardrails (identity, encryption, budgets and alerts) before workloads arrive.
- Train your team and document runbooks for the new environment.
Frequently asked questions
What are the 7 Rs of AWS migration? Retire, Retain, Rehost, Relocate, Repurchase, Replatform and Refactor: seven strategies for moving each application to AWS or deciding not to.
Which AWS migration strategy is the fastest? Rehosting (lift and shift) is usually the fastest, because applications move with minimal changes.
Is lift and shift a good idea? It is a good first step when time matters, but most cost and scalability benefits come from replatforming or refactoring afterwards.
How long does an AWS migration take? A few applications can move in weeks; a full data centre migration typically takes several months and is done in waves.
Which AWS tools help with migration? AWS Migration Hub for tracking, Application Migration Service for servers, Database Migration Service for databases, DataSync for files and Migration Evaluator for business cases.
Planning a move to AWS?
Vibidsoft plans and carries out cloud migrations, from lift-and-shift to full modernisation, and keeps your systems secure, monitored and cost-efficient afterwards. See our cloud and DevOps services and our guide to scaling web applications, or contact us for a migration assessment.
