Migration Approaches: Rehost, Replatform, Refactor—Business Considerations for Each

Cloud migration, the process of moving applications, data, and workloads from on-premises or legacy infrastructure to the cloud—is a strategic initiative undertaken by many organizations to harness cloud benefits such as scalability, cost savings, and agility.

Choosing the right migration approach is critical to maximize value while minimizing risk, complexity, and downtime.

The three primary approaches, rehost, replatform, and refactor offer distinct paths with different business implications suited to varying priorities and resource availability.

Rehost (Lift and Shift)

Rehosting involves moving applications exactly as they are from the source environment to the cloud with minimal or no changes. Often called “lift and shift,” this approach is typically the fastest migration route and requires less upfront effort.

Business Considerations:

1. Speed: Ideal for quick migration when minimizing downtime is essential.

2. Cost: Lower initial migration cost, but may not take immediate advantage of cloud-native features.

3. Risk: Reduced complexity lowers migration risk but may result in suboptimal performance or higher long-term operating costs.

4. Use Cases: Legacy applications that need to be moved urgently, or where code changes are too costly or risky.

Replatform (Lift, Tinker, and Shift)

Replatforming involves making some optimizations during migration without changing the core architecture. This might include switching databases, leveraging managed services, or making minor code adjustments to improve performance in the cloud.

Business Considerations:

1. Performance: Balances migration speed with improved cloud utilization.

2. Cost Efficiency: Can reduce cloud costs compared to rehosting through optimizations.

3. Complexity: Moderate complexity requiring some development resources but less than a full refactor.

4. Use Cases: When some improvements and cloud benefits are desired without a major overhaul.

Refactor (Re-architect)

Refactoring means completely redesigning or re-architecting applications to exploit cloud-native features such as microservices, containers, serverless architecture, or event-driven systems.

Business Considerations:

1. Innovation: Maximizes cloud benefits like scalability, resilience, and agility.

2. Cost: Potentially higher upfront investment, but optimized operational costs and flexibility.

3. Risk: Higher complexity and longer migration timeline requiring development expertise.

4. Use Cases: Strategic applications critical for business innovation or modernization, where long-term cloud advantages outweigh migration effort.