What Is Cloud Migration

Cloud migration is the process of moving applications, data, infrastructure and workloads from on-premises environments to one or more cloud hosted platforms or between cloud environments. At a basic level, this allows businesses to leverage cloud-native resources (designed specifically for cloud environments) and modernize their infrastructures, which translates to fewer idle resources, better uptime and improved business agility.

Migration plays a critical role in paving the way for meaningful business transformation. And in the current AI era, it’s the entry ticket to competitive advantage.

AI may be one of the newest drivers for cloud migration, but there are a number of factors that vary migration strategies — including cost considerations, system and architecture complexity, modernization goals and business alignment. It requires careful planning, execution and ongoing evaluation as migration is no longer a one-time effort or single motion. Today, cloud migration is more of an ongoing operating model that helps organizations ensure the right architectural mix is always in place to meet evolving business needs.

The reasons organizations migrate to or between cloud environments span a broad set of motivations. Here's a quick breakdown of the most common reasons.

Scalability and elasticity: On-premises infrastructure is sized for peak load, meaning you're either over-provisioned (wasting money) or under-provisioned (failing under demand). Cloud allows organizations to scale up in minutes and scale down just as quickly — critical for businesses with seasonal demand, product launches or unpredictable growth.

Cost Economics: The goal isn't just about spending less, it's about shifting from unpredictable capital expenditure (buying and maintaining hardware) to flexible operational expenditure (paying for what you use).

Speed of innovation: Cloud providers offer hundreds of ready-to-consume managed services, freeing up internal resources from building and maintaining in-house equivalents so they can focus on innovation.

Business continuity and resilience: Legacy data centers often have single points of failure. Cloud providers offer built-in resiliencies that would cost enormous sums to replicate on-premises.

Security and compliance: Cloud providers invest billions annually in security infrastructure that most enterprises just can't match internally. This includes identity management as well as regulatory compliances.

Remote work and global collaboration: Applications and data hosted in the cloud are accessible from anywhere, enabling distributed workforces without requiring complex VPN infrastructure or maintaining multiple regional data centers.

AI and data readiness (the new driver): Cloud and AI go hand in hand. AI workloads demand elastic compute, GPU access and dynamic resource allocation that legacy data centers cannot provide cost-effectively.

The type of migration an organization undertakes depends on what's being moved, why and where it's going. There’s often overlap between these types of migration strategies, and they frequently run in parallel to one another. Sometimes that’s by design, and sometimes it’s by necessity, as is often the case with data center migration and application migration.

Data Center Migration
Data center migration refers to shifting on‑premises infrastructure to the cloud. This process typically involves moving the entire stack of servers, storage, networking and related systems from a physical data center environment to a cloud provider’s platform. The migration is often driven by factors such as expiring data center leases, hardware reaching end-of-life or the need to modernize legacy environments. The goal here is to transition the core IT backbone to a scalable, resilient cloud foundation.

Application Migration
Application migration is the process of moving specific applications from an on-premises environment to the cloud, or from one cloud to another. Unlike data center migration, which targets the whole infrastructure, application migration focuses on individual software systems as part of modernization efforts. Organizations may choose to migrate applications independently, rehosting them as-is, refactoring them for cloud-native functionality or even retiring outdated ones. This type of migration often occurs in parallel with data center migration, depending on business needs and technical requirements. Each application’s complexity, dependencies and readiness for the cloud must be evaluated to ensure a smooth transition and maximize the benefits of cloud adoption.

Cloud-to-Cloud Migration
Transitioning services between cloud platforms for cost, performance or vendor flexibility. Cloud-to-cloud migration often emerges mid-program rather than as a planned initiative. An organization might begin migrating to one cloud provider, only to discover mid-execution that a critical workload performs better or costs less on a different platform. Mergers and acquisitions is another example that forces cloud-to-cloud migrations in order to consolidate or interoperate.

Hybrid and Multicloud Migrations
Hybrid cloud solution architecture combines on-premises infrastructure with public or private cloud services, while multicloud solution architecture leverages multiple cloud providers simultaneously to reduce risk and improve flexibility.

Both Hybrid and multicloud migrations involve operating across multiple environments to optimize control, resilience and scalability. These architectures are also frequently the result of running multiple migration types at once.

An enterprise migrating their data center may ultimately determine that moving heavier workloads to public cloud is the best option, where resources and services are consumed on a pay-as-you-go basis and allow for better scalability. This provides flexibility to keep some workloads on-premises or in a dedicated private cloud for more control. This is a hybrid architecture.

Multicloud migration goes further, intentionally distributing workloads across AWS, Azure, Google Cloud or other hyperscalers (providers of large-scale cloud services and infrastructure) to optimize for cost, regulatory compliance, geographic reach or best-of-breed services.

The honest reality is that migration programs at enterprise scale are rarely clean or linear. Organizations that handle this well understand that architecture is an ongoing discipline.

The 7 Rs of cloud migration originally began as 5 Rs: rehost, refactor, revise, rebuild and replace. Gartner came up with this framework early in the enterprise cloud era to give organizations guidance on what kind of cloud moves they should make based on their business needs and where they were at in their cloud journey.

Since then, it has evolved into the 7 Rs (with contributions from AWS and others) to encompass a comprehensive range of cloud migration strategies, including virtualization or when some workloads need to remain on-premises.

1. Rehost (Lift-and-Shift): Move applications without modification.

   Best for: Organizations that need to migrate quickly or have legacy applications that are difficult to modify.

   Rehosting is ideal when speed is critical, such as when you’re facing a data center lease expiration or hardware end-of-life. It requires minimal changes to applications and is generally the simplest and fastest migration path.

   This approach is also well-suited for legacy systems where rewriting or rearchitecting would be costly or risky. By moving applications as-is, businesses can immediately benefit from cloud infrastructure without disrupting operations.

2. Replatform: Make small optimizations without changing core architecture.

   Best for: Applications that would benefit from cloud features like scalable storage and managed services, but don’t require a full redesign.

   Replatforming allows organizations to take advantage of cloud-native capabilities without the complexity and expense of a complete overhaul. It’s a practical choice for applications that need slight adjustments (e.g., upgrading the operating system or moving to a managed database) to improve performance or reduce management overhead while preserving the overall structure.

3. Refactor/Rearchitect: Redesign applications to leverage cloud-native capabilities.

   Best for: Applications that need to scale, improve resilience, or take full advantage of cloud services.

   Refactoring or rearchitecting is recommended when systems need improved scalability and availability for better performance and agility. A redesign like this not only provides enhanced functionality, but allows for cost savings and future-readiness.

4. Repurchase: Replace existing applications with SaaS solutions.

   Best for: When a commercial software as a service (SaaS) product can deliver better functionality, lower cost or increased efficiency compared to maintaining a custom solution.

   Repurchasing is a strong option when adoption of a modern SaaS platform allows organizations to minimize or eliminate the burden of maintenance and upgrades, freeing up internal IT resources. This approach works well for standard business functions such as CRM, HR or email, where SaaS offerings can easily replace existing tools.

5. Retire: Decommission applications that are no longer needed.

   Best for: Applications that are obsolete, redundant or whose business value no longer justifies their upkeep.

   Retiring applications helps organizations reduce complexity, save costs and focus resources on critical workloads. It’s best used when an assessment reveals certain applications are no longer in use, have been replaced or don’t align with current business goals.

6. Retain: Keep certain workloads on-premises due to compliance or technical constraints.

   Best for: Workloads that cannot be migrated because of regulatory, security or unique technical requirements.

   Retaining makes sense when applications require low latency, have strict data sovereignty rules or depend on specialized hardware. Retention ensures continued compliance and operational stability while allowing other workloads to migrate.

7. Relocate: Move workloads at the infrastructure level without modifying applications (e.g., VMware migration).

   Best for: Organizations using virtualization platforms who want to shift infrastructure to the cloud without refactoring applications.

   Relocation is best for enterprises with large investments in virtualization (like VMware) who wish to move their entire infrastructure stack to cloud platforms, including infrastructure as a service (IaaS) and antage.html">platform as a service (PaaS). This preserves existing application configurations and minimizes disruption, allowing IT teams to leverage cloud benefits while maintaining familiar operations.

1. Assess Applications and Workloads

   Every successful migration begins with full visibility into the current environment. This means inventorying applications, mapping interdependencies, evaluating performance requirements, and understanding data sensitivity, governance obligations, and compliance boundaries.

   In practice, this step increasingly includes assessing AI readiness. A thorough assessment helps organizations:

   • Identify which workloads are ready to migrate, modernize or retire
   • Surface hidden dependencies that could create risk or delay
   • Establish a realistic baseline for cost, performance and complexity
   • Prioritize data cleanup and governance work that unlocks AI adoption downstream

    

2. Choose a Cloud Migration Strategy for Each Workload

   Once the portfolio is understood, the next step is selecting the right approach for each application. This is where the 7 Rs framework provides a practical decision model. Not every workload warrants the same investment, and not every workload belongs in the cloud. Aligning migration strategy to business value avoids unnecessary complexity and cost.

   At this stage, organizations should:

   • Determine which of the 7 Rs is the best fit based on workload complexity, business criticality and modernization goals
   • Weigh speed of migration against the long-term benefits of refactoring for cloud-native and AI-ready architectures
   • Make deliberate decisions about multicloud and hybrid placement based on performance, sovereignty and compliance requirements

    

3. Build a Migration Plan With Governance Built In

   With strategy defined, organizations can develop a detailed migration plan that turns intent into execution. In today's environment, governance, security and AI readiness are not afterthoughts to be added later — they are design requirements that must be embedded from the start.

   A well-structured plan addresses:

   • Migration wave sequencing based on dependency mapping and business priority
   • Tooling and platform selection, including AI-assisted migration tools for automated discovery and workload sizing
   • Landing zone architecture with identity-first security, policy-as-code, and compliance guardrails in place before workloads arrive
   • FinOps foundations — cost tagging, budgeting, and commitment planning — established before spend begins
   • Risk identification and mitigation strategies for each wave

    

4. Execute, Validate and Iterate

   The execution phase moves applications, data and workloads into the cloud in prioritized waves. Phased execution — rather than big-bang cutovers — consistently reduces risk and enables teams to learn and adjust between waves. AI-powered migration tools can play a significant role here, automating dependency analysis, generating test cases and providing real-time failure detection and rollback capability.

   Key activities include:

   • Migrating workloads in structured waves, sequenced by complexity and criticality
   • Validating application functionality, integration points and performance against pre-migration baselines
   • Confirming data integrity, access controls and security posture at each stage
   • Capturing lessons from early waves to inform and improve subsequent ones

    

5. Optimize and Innovate

   Migration is not the finish line — it is the beginning of a continuous operating discipline and meaningful innovation. The organizations that realize the full value of cloud recognize that optimization is an ongoing discipline that sets the foundation for business transformation. In other words, AI readiness, where cloud-resident, well-governed data becomes the foundation for deploying intelligent applications, automation and agentic workflows that simply weren't possible on legacy infrastructure.

   Continuous optimization and innovation focuses on:

   • Performance tuning and reliability improvement using cloud-native tools
   • Cost governance through cloud economics and FinOps practices — rightsizing, reserved capacity planning and eliminating idle resources
   • Security posture and compliance alignment
   • Progressive adoption of cloud-native and AI-native services to accelerate development and reduce operational burden
   • Activating clean, governed, cloud-resident data
   • Identifying and automating manual business processes through agentic workflows

We already know cloud migration offers significant business advantages including increased agility, scalability, reliability and performance. But migration also carries real risks that should be considered and planned for ahead of time, not discovered mid-execution.

Clear-eyed planning, best practices and a realistic understanding of where programs commonly go wrong can be the difference between a purely technical exercise and business transformation. Below, we provide an at-a-glance summary for the primary benefits, challenges and best practices of cloud migration to consider.

Cloud Migration Benefits at a Glance

• Agility and scalability: Respond to demand and business change without the constraints of fixed on-premises capacity.
• Reliability and performance: Access globally distributed, redundant infrastructure that most enterprises cannot cost-effectively replicate on their own.
• Security and compliance: Leverage the security investment, certifications and threat detection capabilities that the major cloud providers maintain at a scale most in-house teams cannot match.
• Faster innovation: Put cloud-native and AI-native services within reach: managed data platforms, serverless compute, machine learning pipelines and agentic automation that transform what teams can build and how quickly they can deliver it.

Cloud Migration Challenges/Risks at a Glance

• Cost overruns: Cloud spend grows quickly without FinOps discipline. Proper tagging, budgeting and rightsizing must be established before workloads move, not after bills arrive.
• Downtime and disruption: Incomplete dependency mapping and rushed cutover planning are the most common causes of business disruption during migration.
• Data security and compliance: Frameworks like GDPR, HIPAA and emerging AI governance mandates require data residency, access controls and audit trails to be explicitly designed into the cloud environment from the start.
• Vendor lock-in: Deep reliance on a single provider's proprietary services

Cloud migration is a foundational strategic decision that shapes an organization's capacity to compete, innovate and operate in anAI-driven economy into the future. The enterprises poised to lead are those that approach migration deliberately, building cloud environments that are cost-efficient, resilient and continuously aligned to evolving business needs.

From continuous-optimization thinking to powering cloud and AI-native tools and models through modernization, the organizations that understand how to migrate in a way that builds the right long-term foundation will be set to inherit the business advantage. 

At CDW, cloud migration is approached as part of a full lifecycle journey, from initial assessment and strategy through migration execution, and into ongoing management, governance, and innovation. This ensures that organizations don’t just move to the cloud, but also build cloud environments designed to evolve alongside their business—supporting new workloads, scaling with demand, and enabling future-ready capabilities like AI, automation and advanced analytics.

Build the Right Cloud Foundation With CDW
Whether you’re in the early stages of evaluating cloud adoption or looking to optimize an existing environment, CDW brings the expertise, structured approach and lifecycle support needed to turn cloud migration into a lasting competitive advantage.