Modern enterprises face a critical challenge: how to transition legacy systems to the cloud while maintaining business continuity and maximising return on investment. With 94% of enterprises already using cloud services, the question isn’t whether to migrate, but how to execute a successful cloud migration that aligns with strategic business objectives.
Key takeaways
The Rs of cloud migration framework represents more than just technical strategies – it’s a business-driven approach to transformation:
- The 7 Rs framework (Rehost, Relocate, Replatform, Refactor, Repurchase, Retire, Retain) provides a comprehensive strategy for cloud migration planning that balances technical requirements with business objectives.
- Tailored approaches: each migration strategy serves different business needs, from quick lift-and-shift approaches to complete application re-architecture, enabling organisations to optimise resource allocation.
- Decision framework: proper strategy selection depends on factors like application complexity, budget constraints, technical expertise, and business timelines, requiring thorough portfolio analysis.
What are the “7 Rs” of cloud migration?
This migration framework helps organisations systematically assess their application portfolios and determine the most suitable cloud migration strategy based on technical requirements, business objectives, and available resources.
Originally developed by Gartner as the 5 Rs in 2010, AWS expanded it to 6 Rs in 2016, and later to 7 Rs by adding the Retain strategy to address real-world enterprise complexities.
Cloud migration involves transferring applications, data, and infrastructure from traditional data centers to cloud platforms like AWS Cloud, Microsoft Azure, or Google Cloud. The migration process requires careful planning to ensure business continuity while leveraging cloud native capabilities for improved performance and cost efficiency.
Each strategy within this comprehensive migration framework addresses specific scenarios and constraints, helping organisations balance speed, cost, and transformation goals.
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Rehost (Lift and Shift)
The rehost migration strategy, commonly known as ‘lift and shift’, moves existing applications to cloud infrastructure without modifying code or architecture.
This approach preserves the workload’s existing storage, networking, and compute configurations while transitioning from on premises platform to cloud instance environments. It involves leveraging cloud Infrastructure-as-a-Service offerings to redeploy workloads on a cloud instance.
Implementation characteristics:
- Fastest migration approach with minimal disruption to business operations
- Requires limited cloud expertise, making it accessible for organisations beginning their cloud journey
- Maintains existing operational and configuration constructs
- Ideal for legacy workloads that function adequately in their current state
Business applications: Organisations typically choose rehost lift and shift strategies when facing urgent timelines, such as data center operational costs escalation or lease expirations. This approach works particularly well for stable legacy applications that don’t require immediate modernisation but need quick transition to cloud infrastructure.
Limitations to consider: While rehost strategies enable rapid cloud adoption, they don’t leverage cloud native features like autoscaling or managed services. Organisations may miss opportunities for cost optimisation and performance improvements available through cloud services.
Read more about application modernisation:
- Application modernisation: a guide for business leaders
- How to re-engineer applications to achieve scalability?
Relocate (Hypervisor-Level Lift and Shift)
Relocate hypervisor level lift strategies migrate entire virtual environments or platforms to cloud equivalents without touching individual applications.
This approach moves workloads at the infrastructure layer, often transferring complete VMware environments to cloud platforms or Kubernetes clusters to managed services.
Technical approach:
- Migrates virtual machines and hypervisor configurations intact
- Ensures clients remain seamlessly connected during the migration phase
- Workloads remain intact with minimal configuration changes
- Reduces operational overheads by eliminating physical hardware management
Strategic advantages: The relocate strategy offers the fastest path to cloud adoption for organisations with significant investments in virtualisation technologies. It eliminates data center operational costs while maintaining familiar operational environments for IT teams.
Optimal use cases: This migration strategy excels for bulk migrations of tightly integrated systems or when organisations want to maintain existing VMware investments while gaining cloud infrastructure benefits.
Replatform (Lift and Reshape)
Replatform strategies involve selective modifications to applications during migration, typically upgrading supporting infrastructure while keeping core application code unchanged.
This approach balances migration speed with optimisation opportunities available through cloud based services.
Implementation scope:
- Replaces specific components with cloud native alternatives
- Upgrades databases to managed services like Amazon RDS
- Implements cloud-based load balancing and security services
- Maintains application’s architecture while improving infrastructure
Business value proposition: Organisations can achieve improved performance, security, and compliance while reducing licensing costs and operational complexity. The replatform approach delivers measurable improvements without the extensive development effort required for complete re-architecture.
Examples in practice: Common replatform scenarios include migrating from self-managed databases to managed cloud services, replacing on-premises load balancers with cloud alternatives, or upgrading storage systems to leverage cloud capabilities.
Read more about Replatforming:
Refactor (Re-architect)
Refactor strategies completely re-architect applications to leverage cloud native features and modern architectural patterns.
This comprehensive approach transforms legacy systems into cloud-native deployments optimised for scalability, resilience, and performance. The refactor migration strategy requires re-architecting workloads to support cloud-native capabilities from the ground up.
Transformation scope:
- Breaks monolithic applications into microservices architectures
- Implements serverless computing for improved scalability
- Adopts distributed load balancing and auto-scaling capabilities
- Redesigns data persistence and integration patterns
Investment considerations: While refactoring requires the highest upfront investment and significant cloud expertise, it delivers maximum long-term benefits including improved agility, reduced operational costs, and enhanced competitive capabilities.
Strategic timing: Organisations typically choose refactor approaches for business critical workloads that require enhanced performance, scalability, or integration with modern cloud services. This strategy aligns with innovation-driven objectives and long-term digital transformation goals.
Read more about Rearchitecting:
Repurchase (Drop and Shop)
The repurchase drop and shop strategy replaces existing applications with cloud-native software as a service alternatives.
This approach shifts organisations from traditional licensing models to consumption-based subscription services while outsourcing infrastructure management.
Transformation approach:
- Migrates from on-premises solutions to SaaS platforms
- Examples include replacing Exchange with Microsoft 365 or CRM systems with Salesforce
- Transfers maintenance and infrastructure responsibilities to vendors
- Enables immediate access to modern features and capabilities
Business impact: Repurchase migration strategy often reduces total cost of ownership while providing access to continuously updated functionality. Organisations benefit from efficient regulatory governance and compliance management through vendor certifications.
Implementation considerations: While repurchase strategies reduce operational overhead, they require careful data migration planning and user training. Organisations must evaluate feature compatibility and customisation requirements before transitioning to SaaS alternatives.
Retire
The retire strategy identifies and decommissions applications that provide minimal business value, focusing resources on valuable workloads during the migration process.
This approach eliminates unnecessary complexity and costs associated with maintaining legacy systems.
Assessment criteria:
- Applications with minimal CPU/memory usage over extended periods
- Redundant systems with overlapping functionality
- Legacy workloads no longer supporting business processes
- Applications with high security risks or maintenance costs
Strategic benefits: Retiring obsolete applications reduces migration scope, eliminates ongoing operational costs, and minimises security risks. This strategy enables IT teams to focus resources on migrating additional workloads that deliver business value.
Implementation process: Successful retirement requires thorough portfolio analysis, stakeholder confirmation, and proper data archival procedures. Organisations typically identify 10-30% of applications as retirement candidates during comprehensive assessments.
You can find more about legacy systems here:
- Legacy system modernisation: challenges and common approaches
- How to plan a successful legacy system migration strategy?
Retain (Revisit)
The retain strategy maintains applications in their current environment when immediate migration isn’t viable or beneficial.
This approach recognises that some workloads must remain on premises due to technical, compliance, or business constraints.
Common scenarios:
- Applications with strict regulatory requirements
- Recently upgraded systems with significant remaining value
- Workloads with complex dependencies requiring future migration
- Applications lacking immediate business justification for cloud transition
Strategic value: Retain strategies enable organisations to focus resources on high-value migrations while maintaining stable operations for complex legacy systems. This approach often serves as temporary positioning for future migration phases.
Planning considerations: The retain strategy should include regular reassessment schedules to evaluate changing business requirements, technology capabilities, and compliance landscapes that might enable future migration.
How do the 7 Rs align with business objectives?
Strategic alignment between cloud migration strategies and business objectives requires careful consideration of organisational priorities, technical constraints, and market dynamics. The migration framework enables organisations to optimise their cloud journey by matching appropriate strategies to specific business outcomes.
Speed and agility focus: Organisations prioritising rapid cloud adoption typically favor rehost and relocate strategies for initial migrations, enabling quick wins while building cloud expertise. These approaches provide immediate infrastructure cost reductions and improved disaster recovery capabilities.
Innovation and competitive advantage: Companies seeking competitive differentiation through technology often invest in refactor strategies for customer-facing applications, leveraging cloud native capabilities to deliver enhanced user experiences and faster feature development cycles.
Cost optimisation priorities: The framework supports various cost optimisation approaches, from immediate savings through retire strategies to long-term operational efficiency through repurchase of efficient cloud based alternatives.
Assure seamless migration to cloud environments, improve performance, and handle increasing demands efficiently.
Modernisation of legacy systems refer to the process of upgrading or replacing outdated legacy systems to align with contemporary business requirements and technological advances.
Can multiple cloud computing strategies be applied within a single migration project?
Yes, it’s common for organisations to apply different strategies to different applications within the same migration project. Modern enterprise cloud migration projects typically employ multiple strategies simultaneously, recognising that different applications have varying technical and business requirements.
This approach (often called ‘portfolio migration’) optimises outcomes by tailoring strategies to specific workload characteristics.
For instance, a company might:
- Rehost legacy applications that are stable and require minimal changes.
- Refactor applications that need to scale or integrate with modern services.
- Retire obsolete applications that no longer provide value.
What factors should influence the choice of cloud migration strategy?
Strategic migration decisions require assessment of technical, business, and organisational factors that impact both implementation success and long-term value realisation.
Business value assessment: evaluate each application’s contribution to revenue generation, customer experience, and operational efficiency. Business critical workloads often justify higher investment in refactor or repurchase strategies, while supporting applications may be candidates for simpler rehost approaches.
Technical complexity evaluation: applications with complex dependencies, custom integrations, or legacy frameworks require careful strategy selection. Legacy workloads with significant technical debt may benefit from repurchase strategies using modern SaaS alternatives.
Compliance and regulatory considerations: highly regulated industries must consider data sovereignty, audit requirements, and compliance frameworks when selecting migration strategies. These factors often influence retain decisions or drive specific security requirements for cloud migration approaches.
Resource and timeline constraints: available cloud expertise, budget limitations, and business timelines significantly impact strategy selection. Organisations with limited cloud experience may start with rehost strategies while building capabilities for future refactor initiatives.
Looking for more information about migrating to the cloud?
- Cloud Migration & Modernisation Services
- Untangling modernisation complexities through strategic collaboration
- Cloud readiness assessment: a comprehensive guide for businesses
Stay competitive and ensure long-term business success by modernising your applications. With our approach, you can start seeing real value even within the first 4 weeks.
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