Cloud Migration Strategy: Types, Process, and How to Choose the Right Approach

A cloud migration strategy is a documented plan that defines how your business moves data, applications, and IT workloads from on-premises infrastructure to a cloud environment hosted by providers like AWS, Azure, or Google Cloud. It covers which method to use for each workload, the timeline, budget constraints, risk tolerance, and rollback procedures. Your team gets a structured path rather than an improvised move.

Key Takeaways

The 7 Rs framework covers every migration scenario from a simple lift-and-shift to a full application rebuild.
Skipping the discovery and assessment phase is the leading cause of cloud migration cost overruns.
Rehosting moves applications to the cloud without code changes, making it the fastest migration path.
Retiring unused applications before migration can reduce your cloud bill from day one.
Encryption in transit is a non-negotiable requirement for any migration handling sensitive business data.

What Is a Cloud Migration Strategy?

A cloud migration strategy is the plan that determines exactly how each of your IT workloads moves from your current environment to the cloud. Without one, you’re making individual decisions under pressure rather than executing a coordinated plan. That’s when costs spike and systems go offline unexpectedly.

Think of it this way: signing up for AWS or Azure is like leasing office space. A migration strategy is the moving plan that tells you what goes where, in what order, and what happens if something breaks during the move.

Organizations move to the cloud for three primary reasons: reducing IT infrastructure costs by shifting from capital expenditure (buying servers) to operational expenditure (paying monthly for cloud capacity); improving scalability, which means your systems can handle a spike in demand without buying hardware ahead of time; and strengthening disaster recovery, the process of restoring systems after an outage or data loss event.

A migration strategy differs from simply subscribing to a cloud service. You might sign up for Microsoft Azure tomorrow, but without a defined approach for each application, you risk running duplicate systems, missing dependencies, or moving workloads that weren’t ready for the cloud. The strategy document answers three questions before any data moves: what are we moving, how are we moving it, and what does success look like.

The scale of cloud migration decisions is significant at every level. The U.S. federal government identified $20 billion of its $80 billion annual IT budget as a candidate for cloud migration, a figure that signals just how consequential these decisions are when governance and planning don’t keep pace with ambition. (U.S. Office of Management and Budget / Office of the U.S. Chief Information Officer, 2011)

What Are the 7 Cloud Migration Strategies (the 7 Rs)?

The 7 Rs is the industry-standard way to categorize how each application or workload gets moved to the cloud. Originally developed by AWS and widely adopted across the industry, the framework gives your team precise language for every migration scenario, from a simple copy-and-paste move to a complete rebuild from scratch.

Here are all seven strategies with plain-language definitions:

Rehost (Lift and Shift): You move your application to the cloud exactly as it is, with no code changes. This is the fastest path and works well when you need to exit a data center quickly or reduce hardware costs with minimal disruption. Example: moving your on-premises email server to an AWS EC2 virtual machine.
Replatform (Lift, Tinker, and Shift): You make minor adjustments to take advantage of cloud capabilities without rewriting the application. Example: migrating a database to Amazon RDS (a managed database service) so AWS handles backups and patching instead of your team.
Repurchase (Drop and Shop): You retire your existing application and switch to a Software-as-a-Service (SaaS) product that serves the same function. SaaS means you access the software over the internet rather than installing it on your own servers. Example: replacing an on-premises CRM with Salesforce.
Refactor (Re-architect): You redesign the application to be cloud-native, typically breaking it into smaller, independent services called microservices. This takes the most time and investment but delivers the strongest long-term cloud performance. Example: breaking a monolithic ERP system into modular services that scale independently on Google Cloud.
Retire: You identify applications that are no longer useful and decommission them entirely. This step often surprises businesses. Organizations frequently discover that 10–20% of their applications can simply be turned off, reducing both migration scope and ongoing costs.

📌 Organizations retire 10–20% of their applications during migration assessment.
Retain: You keep certain applications on-premises, at least for now. This applies to systems that aren’t ready for the cloud due to compliance requirements, latency sensitivity, or recent infrastructure investment. Retain is not a failure. It’s an honest assessment of what’s actually ready to move.
Relocate: You move infrastructure to the cloud without purchasing new hardware or refactoring applications, typically using VMware Cloud on AWS or a similar hypervisor-compatible solution. Relocate differs from Rehost in that it preserves the entire virtualized environment rather than moving individual workloads.

Most businesses use a combination of these strategies across their application portfolio. A realistic migration plan might rehost 40% of workloads, repurchase another 20% by switching to SaaS tools, retire 15% of unused systems, and retain a handful of applications until compliance questions are resolved.

The 5 Rs vs. the 7 Rs: What Is the Difference?

The 5 Rs is an earlier version of the same framework. The original five strategies were Rehost, Replatform, Repurchase, Refactor, and Retire. Retain and Relocate were added later to give teams more precise language for situations the original model didn’t fully address.

Retain matters because many early migration frameworks assumed everything would eventually move to the cloud. In practice, some workloads should stay on-premises indefinitely, and teams needed a clear way to document that decision rather than leaving it unaddressed. Relocate was added to cover scenarios where organizations move entire virtualized data centers rather than individual applications.

For most SMBs planning their first migration, the 5 Rs cover the core decision logic. You’ll encounter vendors and consultants referencing both versions, so knowing the distinction helps you follow the conversation. The underlying logic is identical. The 7 Rs model simply adds two categories that matter more at larger scale or in highly regulated industries.

What Are the 7 Steps of a Cloud Migration Model?

The cloud migration process follows a sequential, repeatable model regardless of which strategy type you choose. Skipping early steps, especially discovery and assessment, is the most common cause of cost overruns and unplanned downtime.

Discovery and Inventory: Document every application, server, database, and dependency in your current environment. You can’t plan a move if you don’t know what you have. Tools like AWS Migration Hub and Azure Migrate automate much of this scanning process, generating reports that show which systems talk to which and what each workload requires to function.
Assessment and Cloud Readiness Scoring: Evaluate each workload against cloud readiness criteria: age of the application, licensing compatibility, data sensitivity, and performance requirements. Assign each workload one of the 7 Rs strategies based on this assessment. Dependency mapping, which means identifying which applications rely on which databases or services, is part of this step and prevents the most painful surprises during cutover.
Build the Business Case: Translate your technical assessment into financial terms. Calculate the total cost of ownership (TCO) for staying on-premises versus migrating, factoring in hardware refresh cycles, licensing, staffing, and the cost of downtime risk. This step gets leadership buy-in and defines success metrics.
Choose a Cloud Provider and Architecture: Select your provider (AWS, Azure, Google Cloud, or a combination) based on workload requirements, existing licensing agreements, and your team’s skill set. Define your target architecture: will you use a public cloud, a private cloud hosted by the provider, or a hybrid cloud model that keeps some workloads on-premises while moving others?
Pilot Migration: Move a low-risk, non-critical workload first. This is your proof-of-concept. The pilot reveals hidden dependencies, tests your runbook (the step-by-step migration playbook), and gives your team hands-on experience before you migrate business-critical systems. Organizations that skip the pilot phase regularly report the most disruptive cutovers.
Execute Migration in Waves: Migrate workloads in planned waves, grouped by dependency and business priority. Start with the simplest rehost candidates, then move to more complex replatform and refactor workloads in later waves. Encrypt all data in transit during this phase. Encryption scrambles data so it can’t be read if intercepted during the transfer between your data center and the cloud provider’s network.
Optimize and Monitor: Once workloads are running in the cloud, right-size your resources. Cloud environments make it easy to over-provision, paying for compute and storage you don’t use. Tools like AWS Cost Explorer and Azure Cost Management help identify where you’re spending more than necessary. Decommission on-premises hardware only after you’ve confirmed cloud workloads are stable.

The FDIC failed to develop Contract Management Plans for all 17 contract actions covering cloud services valued at over $546 million, a governance gap that is a direct example of what happens when process steps get skipped at scale. (FDIC Office of Inspector General, 2023) Your migration plan document should include scope, phases, success metrics, and rollback procedures for every wave.

How to Choose the Right Cloud Migration Strategy for Your Business

Choosing the right migration strategy comes down to four variables: your timeline, your budget, the technical complexity of your existing applications, and your long-term cloud goals. A business under pressure to exit a data center lease in 90 days has different constraints than a company with 18 months and a modernization mandate.

Apply this decision logic to each workload in your inventory:

Timeline is short, budget is tight: Rehost. Get workloads running in the cloud quickly and optimize later.
You want managed services but can’t rebuild: Replatform. Small adjustments, meaningful operational benefits.
The application does something a SaaS product already handles: Repurchase. Stop maintaining what someone else has already built.
Long-term performance and scalability matter most: Refactor. Accept the higher upfront cost for better architecture.
Nobody can explain what the application does: Retire. Seriously evaluate whether it’s needed at all.
Compliance or latency requirements make cloud migration premature: Retain. Document the decision and revisit in 12 months.

Businesses moving from fully on-premises environments typically start with rehosting before progressing to refactoring. The rehost phase builds your team’s cloud confidence, validates your monitoring and security tooling, and generates the real-world performance data you need to make informed refactoring decisions later.

Strategy	Effort Level	Cost (Relative)	Best Fit
Rehost (Lift & Shift)	Low	Low upfront	Speed priority, data center exit
Replatform	Medium	Low to medium	Managed services, limited code change
Repurchase	Low (technical), Medium (change management)	SaaS subscription replaces CapEx	Off-the-shelf software replacement
Refactor	High	High upfront, lower long-term	Modernization, cloud-native performance
Retire	Very Low	Reduces cost immediately	Unused or redundant applications

Top Cloud Migration Tools to Know

Cloud migration tools fall into four categories: assessment, data transfer, application migration, and monitoring. Using the right tool at each phase reduces errors and gives your team visibility into progress.

Assessment Tools

AWS Migration Hub: A central dashboard that tracks migration progress across AWS services and third-party tools. It maps application dependencies and gives you a single view of which workloads have moved and which are still in progress.
Azure Migrate: Microsoft’s built-in assessment tool for discovering on-premises servers, databases, and web apps. It generates cloud readiness reports and cost estimates for running workloads on Azure.

Data Transfer Tools

AWS DataSync: Automates transferring large data sets from on-premises storage to AWS, with built-in encryption and verification.

📌 AWS DataSync transfers data up to 10 times faster than open-source tools.
Azure Data Box: A physical appliance Microsoft ships to your location when transferring large data volumes over the internet would take too long or cost too much in egress fees.

Application Migration Tools

AWS Application Migration Service (MGN): Handles lift-and-shift migrations by continuously replicating your on-premises servers to AWS, minimizing cutover windows to minutes rather than hours.
Google Cloud Migrate for Compute Engine: Moves virtual machines from on-premises environments or other clouds to Google Cloud with minimal downtime.

Monitoring Tools

AWS Cost Explorer: Breaks down cloud spending by service, region, and resource to identify over-provisioned workloads after migration.
Azure Monitor: Tracks performance, availability, and security across Azure workloads, feeding alerts to your team when thresholds are breached.

Common Cloud Migration Challenges and How to Avoid Them

Cloud migrations fail, or run significantly over budget, for predictable reasons. Understanding these failure points before you start is far cheaper than discovering them mid-migration.

Underestimating Application Dependencies

Many organizations discover during migration that applications they thought were standalone actually depend on shared databases, internal APIs, or network configurations that weren’t documented. Dependency mapping during the assessment phase catches these connections. Moving an application without its dependencies causes outages that are entirely avoidable.

Skipping the Pilot Phase

Organizations that move directly from assessment to full migration regularly encounter surprises that a pilot would have surfaced. The pilot phase isn’t overhead. It’s insurance. Run your first migration on a workload you can afford to take offline temporarily and treat every problem you find as useful data rather than a setback.

Cost Overruns Post-Migration

Cloud costs frequently exceed projections when teams migrate more workloads than planned or fail to right-size resources after go-live. On-premises environments run servers at 10–20% utilization; cloud environments bill for every hour a resource runs.

📌 On-premises servers average just 10–20% utilization before cloud migration.

Set a 60-day optimization window immediately after each migration wave and use cost management tools to identify idle resources.

Security Configuration During the Move

Data in transit is vulnerable if encryption isn’t configured correctly. In transit means data moving from your data center to a cloud provider’s network. Encryption scrambles that data so it can’t be read if intercepted. Every migration involving customer records, financial data, or personally identifiable information requires encryption in transit as a baseline requirement, not an optional enhancement. Access controls, identity verification, and audit logging should be configured before the first workload moves, not after.

Building a Cloud Migration Strategy That Works

A sound cloud migration strategy starts with an honest inventory of what you have, assigns the right strategy type to each workload, and follows a sequential process that builds confidence before complexity. The 7-step process applies regardless of whether you’re rehosting a single server or refactoring a dozen applications.

Your next three actions should be:

Run a discovery scan of your current environment using AWS Migration Hub or Azure Migrate to understand what you’re actually working with.
Apply the 7 Rs framework to each application in your inventory, starting with the most obvious candidates for retirement and rehosting.
Evaluate cloud providers based on your specific workload requirements, not on brand familiarity, and use a provider comparison guide to shortlist the right platform before committing.

If your inventory reveals a mix of legacy applications, compliance-sensitive data, and time pressure, a cloud migration readiness assessment can map your workloads to the right approach and identify the gaps that most commonly derail migrations before they begin.

Frequently Asked Questions

What is a cloud migration strategy?

A cloud migration strategy is a documented plan that defines how your business moves data, applications, and IT workloads from on-premises infrastructure to a cloud environment. It specifies which method to use for each workload, the sequence of migration waves, the timeline, budget, success metrics, and rollback procedures. Without a strategy, migrations tend to run over budget and create unplanned downtime.

What are the types of cloud migration strategies?

The main types are defined by the 7 Rs framework: Rehost (move as-is), Replatform (move with minor changes), Repurchase (switch to a SaaS product), Refactor (redesign for cloud-native architecture), Retire (decommission unused applications), Retain (keep on-premises for now), and Relocate (move entire virtualized environments). Most businesses use a mix across their application portfolio rather than applying a single approach to everything.

What is the difference between rehosting and replatforming?

Rehosting, often called lift-and-shift, moves an application to the cloud exactly as it is, with no code changes. Replatforming makes targeted modifications, like switching to a managed database service, to gain cloud efficiencies without rewriting the application. Rehosting is faster and cheaper upfront; replatforming delivers more operational benefit at slightly higher initial effort. The right choice depends on how long you plan to run the application and what your team’s capacity allows.

How long does a cloud migration take?

Migration timelines vary widely based on the number of workloads, their complexity, and the strategies applied. A rehost migration for a small business with 10 to 20 applications might take 3 to 6 months including assessment and pilot phases. A full refactor project for a complex application portfolio can take 12 to 24 months or longer. Rushing the assessment and planning phases to shorten the timeline is the most common mistake businesses make.

How do I avoid cost overruns during cloud migration?

Start with a realistic TCO analysis that accounts for data egress fees, licensing changes, and staffing costs, not just compute and storage. Run a pilot migration before committing to full scale. After each migration wave, schedule a 60-day optimization review using tools like AWS Cost Explorer or Azure Cost Management to right-size resources. Also, retire unused applications before migration to reduce the volume of workloads you’re paying to run in the cloud.