When considering a migration to the AWS Cloud, selecting the right strategy is crucial to ensuring a smooth and cost-effective transition. AWS offers a variety of migration strategies known as the “7 Rs”. A framework that helps businesses choose the best path forward for each application in their portfolio. Whether you’re looking to retire outdated systems or modernize legacy applications, these strategies provide clear guidance for businesses of all sizes. Let’s explore each of the 7 Rs and the common use cases for each.

1. Retire⌗

The Retire strategy involves decommissioning or archiving applications that no longer serve any business purpose. This option is ideal when an application is obsolete, inefficient, or no longer beneficial to the business.

Common Use Cases:⌗

  • No Business Value: The application doesn’t provide enough value to justify moving it to the cloud.
  • Cost Reduction: You want to eliminate the expenses associated with maintaining the application.
  • Security Concerns: The app uses outdated components or an unsupported operating system.
  • Zombie or Idle Applications: Low-performance apps with minimal resource usage (e.g., CPU and memory usage below 5%) are prime candidates for retirement.

By retiring obsolete applications, you can reduce operational complexity and improve security while freeing up resources for more critical workloads.

2. Retain⌗

The Retain strategy is for applications that you are not ready to migrate or that need to stay in their current environment for a period of time. This strategy is often temporary and is suitable for applications that require careful planning or are subject to specific regulations.

Common Use Cases:⌗

  • Security and Compliance: Certain applications must stay on-premises to comply with data residency laws.
  • High Risk: Applications with complex dependencies or mission-critical components require more time for evaluation before migrating.
  • Recent Upgrades: If an application was recently upgraded, you may opt to wait until the next scheduled technical refresh before migrating it.
  • Vendor Software Transition: Some applications are better retained until their vendor releases a cloud-native version (e.g., SaaS).

By retaining these applications temporarily, you can ensure that they remain secure and compliant while you assess a migration strategy for them in the future.

3. Rehost (Lift and Shift)⌗

Rehosting, also known as Lift and Shift, involves migrating applications from an on-premises environment to the AWS Cloud without changing the application’s architecture. This strategy is a quick and simple way to move to the cloud.

Common Use Cases:⌗

  • No Changes to the Application: You simply move the application as-is to AWS without worrying about optimization.
  • Minimize Downtime: Rehosting allows you to maintain application availability during the migration, minimizing disruption to end-users.

Rehosting is ideal for businesses looking to migrate quickly and then modernize applications later. Services like the AWS Application Migration Service can automate this process, ensuring a smooth transition.

4. Relocate⌗

The Relocate strategy involves transferring applications or data from one environment to another without changing the application’s architecture. This can include moving applications between on-premises environments or even between different AWS Regions, VPCs, or accounts.

Common Use Cases:⌗

  • Minimal Disruption: Moving applications with little to no impact on users, ensuring minimal downtime.
  • Simple Migration: A straightforward approach when no changes are needed to the architecture, but relocation is necessary for operational reasons.

This strategy is particularly effective for businesses looking to move to the cloud without significant changes to their existing systems.

5. Repurchase (Drop and Shop)⌗

The Repurchase strategy is commonly referred to as “drop and shop.” It involves replacing existing applications with cloud-native solutions, often SaaS (Software as a Service) offerings, which offer enhanced functionality and reduced maintenance burdens.

Common Use Cases:⌗

  • Shift to SaaS: Moving from on-premises software to cloud-based services to reduce infrastructure and licensing costs.
  • Outdated Applications: Replacing legacy applications with more modern, feature-rich alternatives in the cloud.

Repurchasing typically involves a fresh start with a cloud-based application that better meets your business needs. This strategy can help businesses achieve scalability, accessibility, and lower operational costs.

6. Replatform (Lift, Tinker, and Shift)⌗

Replatforming, also known as Lift, Tinker, and Shift, involves migrating applications to the cloud while making some optimizations to leverage cloud capabilities, such as cost savings, scalability, or improved performance.

Common Use Cases:⌗

  • Optimization: Moving applications to managed services like Amazon RDS or using AWS Graviton processors to reduce costs.
  • Performance Improvements: Migrating to more efficient systems or platforms (e.g., moving from a Windows server to Linux for cost savings).
  • Security Upgrades: Updating the operating system or platform to a supported version as part of the migration.

Replatforming allows businesses to make targeted improvements to existing applications while moving to the cloud, balancing the need for optimization with the benefits of cloud-native features.

7. Refactor or Re-architect⌗

The Refactor or Re-architect strategy involves redesigning an application to fully take advantage of cloud-native features, such as serverless computing, microservices, and auto-scaling. This is the most complex and resource-intensive migration strategy, and it is typically used when the business demands major improvements in agility, scalability, and cost-efficiency.

Common Use Cases:⌗

  • Legacy System Overhaul: When an application cannot scale or is costly to maintain, refactoring is used to modernize the architecture for the cloud.
  • Monolithic to Microservices: Moving from a monolithic application to microservices to improve flexibility and development speed.
  • Business Innovation: Refactoring to enable faster delivery of new features or to create more robust and scalable applications.[[]]

While refactoring offers the most long-term benefits, it requires a significant investment in time and resources, making it more suitable for applications with high business impact.

Choosing the Right Strategy for Your Business⌗

Selecting the right migration strategy is critical for a successful cloud transition. While some applications may be ready for immediate rehosting or repurchasing, others may require careful planning and re-architecture. It’s also important to consider your business goals, the complexity of the applications, and the long-term scalability you desire.

For large migrations, we recommend starting with strategies like rehosting, relocating, or replatforming. After the initial migration, businesses can modernize and optimize their applications. Refactoring, while powerful, is often more suitable for smaller-scale, high-priority applications where a complete architectural overhaul is justified.

By leveraging the 7 Rs framework, businesses can make informed decisions that align with their goals and drive a smooth and efficient migration to the AWS Cloud.