The 7 Rs of Cloud Migration in the Age of AI

In the early 1900s, automobile manufacturers faced a critical decision: should they convert horse carriage factories to build cars, or start fresh with purpose-built facilities? Some companies tried to retrofit existing buildings. Others built new factories from the ground up. A few wisely recognized that different products required different approaches. 

Organizations moving to the cloud face remarkably similar decisions today. You have applications built for data centers, designed when infrastructure was something you owned rather than rented. Moving them to the cloud without a clear strategy is like trying to manufacture cars in a carriage factory because the building happens to be empty. 

With 94% of enterprises now using cloud services, the conversation has shifted from "should we migrate?" to "how do we migrate effectively?" The answer starts with understanding that not every application deserves the same treatment. 

What are the 7 Rs of cloud migration? 

The 7 Rs represent seven distinct approaches for moving applications from on-premises infrastructure to cloud environments. Think of them as different renovation strategies for your application portfolio: some applications need simple relocation, others require complete rebuilding, and some shouldn't move at all. 

The seven strategies are: 

1. Rehost - Move applications as-is to cloud infrastructure 
2. Relocate - Transfer entire virtualized environments without changes 
3. Replatform - Make selective optimizations during migration 
4. Refactor - Completely re-architect for cloud-native capabilities 
5. Repurchase - Replace with SaaS alternatives 
6. Retire - Decommission applications that no longer serve business needs 
7. Retain - Keep applications on-premises with plans to revisit 

Most successful migrations use multiple strategies simultaneously. You might rehost 40% of applications for quick wins, replatform 30% for targeted improvements, retire 15% that no longer add value, repurchase 10% with SaaS alternatives, and retain 5% that require more planning. 

At Valorem Reply, we've guided organizations through hundreds of migrations What we've learned: the framework matters more than the specific percentages. The goal is matching the right strategy to each application's unique situation. 

How did the 7 Rs framework evolve?  

The framework didn't appear fully formed. It evolved as organizations learned what actually worked. 

2010: Gartner introduces the 5 Rs: When cloud computing was still relatively new, Gartner created a framework with five migration strategies to help organizations think systematically about their options. Companies were struggling to understand how legacy applications could transition to this fundamentally different infrastructure model. 

2016: AWS adds the sixth R: As migrations matured, AWS recognized something important: not every application deserves to move to the cloud. They added "Retire" to acknowledge that migration projects often reveal applications consuming resources without delivering value. Why pay to migrate something that should be turned off? 

2017: The complete 7 Rs framework emerges: AWS added "Retain" as the seventh strategy, recognizing that hybrid environments are the reality for most enterprises. Some applications need to stay on-premises due to regulatory requirements, recent upgrades, or dependencies requiring more analysis time. 

The framework continues to prove relevant because it addresses real-world constraints. Applications aren't uniform. Business requirements differ. Technical capabilities vary. The 7 Rs provide structure for making systematic decisions about each application in your portfolio. 

When should you rehost applications? 

Rehosting moves applications to cloud infrastructure without changing code or architecture. The application runs on cloud virtual machines instead of on-premises servers, but otherwise stays identical. 

Best used for: 

• Applications facing urgent migration timelines 
• Stable systems working well in their current state 
• Organizations building initial cloud expertise 
• Situations requiring quick cost reduction 

How it works: Your application transfers from physical or virtual servers to cloud instances. Infrastructure changes, but the application itself remains unchanged. You maintain existing configurations, operational processes, and dependencies. 

The tradeoff: rehosting gets you into the cloud fast, but you're not using cloud-native capabilities like auto-scaling or managed databases. You're running data center applications in someone else's data center. For many organizations, that's perfectly fine as a starting point. 

What makes relocate different from rehost? 

Relocate moves entire virtualized environments to the cloud without touching individual applications. Instead of migrating applications one by one, you transfer the entire virtual infrastructure layer. 

Best used for: 

• Organizations with significant VMware investments 
• Bulk migrations of tightly integrated systems 
• Situations requiring minimal downtime 
• Teams wanting familiar operational environments 

How it works: VMware environments move to Azure VMware Solution. Kubernetes clusters migrate to Azure Kubernetes Service. Your operations teams continue working with familiar tools while gaining cloud infrastructure benefits. 

The key advantage: this is the fastest path to cloud for virtualized workloads. Your staff doesn't need retraining on new platforms. Operational procedures stay consistent. You eliminate data center costs while maintaining the virtualization layer your team knows. 

The limitation: you're still not taking full advantage of cloud-native services. Relocate is often a first step, with further optimization happening once applications are running in the cloud. 

Replatforming makes targeted improvements during migration without changing core application architecture. You're optimizing specific components while keeping most of the application intact. 

Best used for: 

• Applications that would benefit from managed services 
• Organizations balancing speed with improvement 
• Systems with specific performance issues 
• Teams with moderate cloud expertise 

How it works: You might migrate a self-managed database to Azure SQL Database, replace on-premises load balancers with Azure Load Balancer, or upgrade storage to use cloud capabilities. The application code largely stays the same. 

Replatforming typically delivers 20-40% improvements in performance or cost without the extensive timeline of complete re-architecture. You get meaningful benefits while maintaining the application's fundamental design. 

When does refactoring make business sense? 

Refactoring completely rearchitects applications to be cloud-native from the ground up. You're not just moving to the cloud. You're reimagining how the application works. 

Best used for: 

• Customer-facing applications requiring significant scale 
• Systems where current architecture blocks business capabilities 
• Organizations with strong cloud development expertise 
• Strategic applications central to competitive advantage 

How it works: This typically means breaking monolithic applications into microservices, using serverless functions, adopting container orchestration, and redesigning data patterns. You're fundamentally changing the application's structure. 

Refactoring requires the highest investment but delivers maximum long-term value. Consider this approach when your current architecture prevents adding critical features, when you need to handle significantly higher scale, or when operational costs are unsustainable. 

The business case depends on the application's strategic importance. Refactoring makes sense for applications that differentiate your business or generate significant revenue. Supporting applications rarely justify this investment. 

Should you replace or rebuild applications?  

Repurchasing replaces existing applications with SaaS alternatives. Instead of migrating your custom-built system, you adopt a commercial solution that's already cloud-native. 

Best used for: 

• Applications where SaaS solutions offer equivalent features 
• Systems with high maintenance costs relative to value 
• Organizations wanting to focus resources on differentiation 
• Situations where licensing costs make SaaS more economical 

How it works: You might replace a custom CRM with Dynamics 365, move from on-premises email servers to Microsoft 365, or swap homegrown systems for purpose-built SaaS platforms. You're trading infrastructure management burden for subscription fees. 

Repurchasing often reduces total cost of ownership while providing continuous updates and modern features. However, you need to carefully plan data migration, account for customization limitations, and invest in user training for the new platform. 

Which applications should you retire? 

Retiring means decommissioning applications that no longer provide business value. Migration projects force you to inventory everything running in your data center. You'll discover applications that consume resources without delivering meaningful returns. 

Best used for: 

• Redundant systems with overlapping functionality 
• Applications with minimal usage patterns 
• Legacy systems creating security risks 
• Shadow IT discovered during assessment 

Why it matters: Many organizations identify 10-30% of applications as retirement candidates during assessments. Eliminating these before migration reduces project scope, ongoing costs, and security exposure. 

The opportunity: every application you retire is one you don't have to migrate, secure, or maintain. The cost savings and risk reduction often exceed the benefits of migrating low-value systems. 

Migration projects naturally reveal retirement candidates. Usage monitoring shows applications with minimal activity. Stakeholder interviews uncover systems that were replaced informally. Dependency mapping identifies applications that nothing actually depends on anymore. 

What stays on-premises?  

Retain means keeping applications in their current environment with plans to revisit the decision later. This isn't a failure to migrate. It's recognizing that some applications aren't ready or appropriate for cloud migration right now. 

Best used for: 

• Applications with strict regulatory requirements not yet addressed 
• Recently upgraded systems where migration doesn't justify costs 
• Workloads with complex dependencies needing more analysis 
• Applications without clear business justification 

Strategic value: Retain isn't a permanent decision. It's a pause button. You can focus resources on high-value migrations while maintaining stability for applications requiring more planning time. 

Common scenarios: applications running on mainframe systems, specialized industrial equipment software, or systems with compliance requirements demanding on-premises deployment often start in this category. 

The key is setting review timelines. Applications marked "retain" should be reassessed every 6-12 months as cloud capabilities evolve, compliance frameworks update, or business requirements change. 

How do you choose the right strategy? 

Choosing the right strategy requires evaluating multiple factors for each application: 

Business criticality and strategic value: 

• Revenue-generating customer applications often warrant refactoring investment 
• Supporting systems may be candidates for rehost or repurchase 
• Low-value applications should be evaluated for retirement 

Technical characteristics: 

• Applications with documented architecture and minimal customization: consider rehost or replatform 
• Highly customized legacy systems: evaluate repurchase alternatives or refactor plans 
• Modern, well-architected applications: may benefit from relocate or replatform 

Compliance and regulatory requirements: 

• Strict data sovereignty needs may require retain decisions initially 
• Industry certifications available through cloud providers can enable migration 
• Regulatory frameworks are increasingly cloud-friendly, but timing varies 

Resource constraints: 

• Limited cloud expertise: start with rehost and relocate strategies 
• Tight timelines: prioritize lift-and-shift approaches 
• Budget considerations: balance immediate costs against long-term operational savings 

Technical debt and architecture quality: 

• Applications with significant technical debt may benefit from repurchase over refactor 
• Well-designed systems are good candidates for replatform optimization 
• Problematic architectures might need complete refactoring or replacement 

As one of the few Microsoft partners with all six Solutions Partner Designations, we help organizations evaluate these factors systematically. Our cloud migration consulting services begin with comprehensive portfolio assessment to match strategies to business objectives. 

Frequently Asked Questions 

What are the 7 Rs of cloud migration?

The 7 Rs are seven migration strategies: Rehost (lift-and-shift), Relocate (hypervisor-level migration), Replatform (selective optimization), Refactor (complete rearchitecture), Repurchase (replace with SaaS), Retire (decommission), and Retain (keep on-premises). Each strategy serves different business needs, technical constraints, and organizational capabilities.

What are the 7 steps of cloud migration?

While the 7 Rs represent strategies, migration execution typically follows these steps: (1) Application portfolio discovery and assessment, (2) Strategy selection for each workload, (3) Architecture design and planning, (4) Proof of concept for complex migrations, (5) Wave-based execution, (6) Testing and validation, and (7) Optimization and continuous improvement. The specific steps vary based on which strategy you apply to each application. 

What are the 7 Rs of modernization?

The 7 Rs apply to both migration and modernization. They represent increasing levels of transformation: Rehost maintains current functionality in cloud infrastructure, Relocate moves environments intact, Replatform selectively modernizes components, Refactor completely re-architects for cloud-native capabilities, Repurchase adopts modern SaaS alternatives, Retire eliminates obsolete systems, and Retain keeps applications on-premises when appropriate. The strategies balance modernization goals with practical constraints.

Which one of the following is one of the 7 Rs of planning a cloud migration?

All seven strategies are valid: Rehost, Relocate, Replatform, Refactor, Repurchase, Retire, and Retain. The important point is that successful migrations use multiple strategies simultaneously. You might rehost stable applications, refactor customer-facing systems, retire redundant tools, and retain applications with compliance constraints within the same program. The framework helps you systematically evaluate which strategy fits each application. 

How long does cloud migration typically take?

Migration timelines vary based on portfolio size, chosen strategies, and organizational readiness. Simple rehost migrations of individual applications complete in 2-4 weeks, while enterprise-wide migrations span 12-24 months. Organizations typically migrate in waves with 4-8 week intervals between waves. Refactor strategies take 3-6 times longer than rehost approaches for the same application but deliver significantly more value. 

What's the difference between rehost and relocate?

Rehost moves individual applications to cloud virtual machines while maintaining the application as-is. Relocate transfers entire virtualized environments (like VMware or Kubernetes) without touching individual applications. Relocate is faster for bulk migrations of virtualized workloads, while rehost gives more flexibility for optimizing individual applications over time.

Should you migrate everything to the cloud?

No. The Retain strategy exists because not every application benefits from cloud migration. Applications with strict regulatory requirements, recent upgrades, or minimal business value relative to migration costs may be better on-premises. Hybrid approaches where some workloads stay on-premises while others move to the cloud are common and often optimal .

Making strategic decisions about your portfolio 

Cloud migration isn't about moving everything as fast as possible. It's about making deliberate choices that align with business objectives while managing risk and resource constraints. 

The 7 Rs framework provides structure for these decisions. Each strategy serves specific scenarios. Understanding when to use each approach turns complex migration programs into systematic, manageable initiatives. 

At Valorem Reply, we've guided organizations through this process. We know that successful migrations start with thorough assessment, continue with strategic planning, and succeed through disciplined execution. 

Whether you're beginning to explore cloud migration or accelerating an existing program, we can help you assess your portfolio, select appropriate strategies, and execute migrations that deliver business value. 

Ready to discuss your cloud migration strategy? Connect with our team to assess your application portfolio and develop an approach aligned with your business objectives. We work with you to evaluate each application systematically and create a roadmap that balances speed, cost, and transformation goals.