Quick Answer
The 7Rs are seven migration strategies AWS uses to categorize how each workload moves to the cloud : Rehost, Replatform, Repurchase, Refactor, Retire, Retain, and Relocate. Each strategy represents a different level of effort, cost, and long-term benefit for the application being migrated. 1. Rehost (Lift and Shift) Rehosting means moving an application to AWS without modifying its code or architecture. The server, operating system, and application stack are replicated as-is onto EC2 instances. This is the fastest migration strategy and works well for organizations that need to exit a data center on a tight deadline. AWS Application Migration Service automates much of the rehosting process. It continuously replicates source servers to AWS, allowing you to test and cut over with minimal downtime. While rehosting does not optimize the application for cloud- native features, it establishes the workload in AWS where future optimization can happen.
Key Topics Covered
The 7Rs are seven migration strategies AWS uses to categorize how each workload moves to the cloud: Rehost, Replatform, Repurchase, Refactor, Retire, Retain, and Relocate. Each strategy represents a different level of effort, cost, and long-term benefit for the application being migrated.
1. Rehost (Lift and Shift)
Rehosting means moving an application to AWS without modifying its code or architecture. The server, operating system, and application stack are replicated as-is onto EC2 instances. This is the fastest migration strategy and works well for organizations that need to exit a data center on a tight deadline.
AWS Application Migration Service automates much of the rehosting process. It continuously replicates source servers to AWS, allowing you to test and cut over with minimal downtime. While rehosting does not optimize the application for cloud-native features, it establishes the workload in AWS where future optimization can happen.
2. Replatform (Lift, Tinker, and Shift)
Replatforming involves making targeted adjustments during migration to take advantage of managed services. A common example is moving a self-managed MySQL database to Amazon RDS. The application logic stays the same, but the underlying platform shifts to a managed equivalent that reduces operational overhead.
This strategy balances speed with optimization. You gain immediate benefits like automated patching, backups, and scaling without rewriting application code. Replatforming is a popular choice for database-heavy workloads where the maintenance burden on-premises is high.
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3. Repurchase (Drop and Shop)
Repurchasing means replacing an existing application with a cloud-native SaaS product. For example, migrating from a self-hosted CRM to Salesforce, or moving from an on-premises email server to Microsoft 365. The legacy application is retired, and users adopt the new product.
This strategy eliminates infrastructure management entirely for the replaced workload. The trade-off is that repurchasing often requires data migration, user retraining, and process changes. It works best for commodity applications where a mature SaaS alternative exists and customization needs are limited.
4. Refactor (Re-architect)
Refactoring involves redesigning the application to use cloud-native architecture. This might mean breaking a monolith into microservices, adopting serverless computing with Lambda, or replacing file-based storage with DynamoDB. Refactoring delivers the greatest long-term benefits but requires the most effort.
Organizations typically refactor applications that need improved scalability, performance, or agility. The investment in re-architecture pays off through lower operating costs, faster feature delivery, and better resilience. Refactoring is rarely applied to every workload; it is reserved for strategic applications with a long future lifespan.
5. Retire
Retiring means decommissioning applications that are no longer needed. During portfolio assessment, organizations frequently discover redundant, obsolete, or unused applications still consuming resources. Retiring these workloads reduces migration scope and eliminates ongoing maintenance costs.
A thorough discovery process often reveals that 10-20% of the application portfolio can be retired. Identifying these candidates early shrinks the migration project, lowers costs, and lets teams focus effort on workloads that deliver business value. Retirement decisions should be documented and communicated to application owners well before migration waves begin.
6. Retain (Revisit)
Retaining means keeping certain applications in their current environment, at least for now. Some workloads have dependencies, compliance requirements, or technical constraints that make immediate migration impractical. Retaining acknowledges these realities and defers migration to a later phase.
Retained workloads should be revisited periodically. As cloud services mature and constraints change, previously retained applications may become candidates for rehosting, replatforming, or refactoring. Retention is not a permanent decision but a deliberate deferral with a planned review cycle set at regular intervals.
7. Relocate (Hypervisor-Level Migration)
Relocating involves moving VMware-based workloads to VMware Cloud on AWS without changing the application, operating system, or hypervisor layer. This strategy is specific to organizations running VMware and provides the fastest path for large VMware estates to reach AWS infrastructure.
Relocation preserves existing VMware tooling and operational procedures. Teams continue using vCenter and familiar management interfaces while benefiting from AWS global infrastructure. It is particularly useful for organizations with significant VMware licensing investments who want to migrate without retraining operations staff or rebuilding automation workflows.
Choosing the Right Strategy
Most migrations apply multiple Rs across the portfolio. Strategic applications get refactored, commodity workloads get rehosted or replatformed, and obsolete systems get retired. The 7R assessment happens during the MAP assess phase and directly informs the migration plan.
A common distribution for enterprise portfolios is roughly 40-50% rehost, 20-30% replatform, 10-15% refactor, and the remainder split between retire, retain, repurchase, and relocate. These ratios vary based on industry, application age, and business strategy. The right mix is determined during portfolio analysis, not assumed in advance.
Working with a migration partner who understands all seven strategies ensures that each workload receives the approach that best fits its technical requirements, business value, and timeline constraints. Learn more about how Opsio applies these strategies through our AWS migration services, or explore how the MAP program structures this assessment.
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Written By
Country Manager, Sweden at Opsio
Johan leads Opsio's Sweden operations, driving AI adoption, DevOps transformation, security strategy, and cloud solutioning for Nordic enterprises. With 12+ years in enterprise cloud infrastructure, he has delivered 200+ projects across AWS, Azure, and GCP — specialising in Well-Architected reviews, landing zone design, and multi-cloud strategy.
Editorial standards: This article was written by cloud practitioners and peer-reviewed by our engineering team. We update content quarterly for technical accuracy. Opsio maintains editorial independence.