by The Computing Australia Group | Cloud Migration
- Cut IT costs
- Improve security and resilience
- Enable flexible, remote work
- Help you adopt new technologies faster
This guide explains cloud migration in plain English – what it is, why it matters, the different models and strategies, and how to plan a migration that actually works for your business (not just your IT wishlist).
What Is Cloud Migration?
In practice, this can mean:
- Moving from your physical server room to a public cloud like AWS, Microsoft Azure, or Google Cloud
- Shifting from an older private data centre to a modern private cloud
- Switching from one cloud provider to another (cloud-to-cloud migration)
- Moving selected workloads back from the cloud to on-premises (reverse migration), usually for cost, performance, or compliance reasons
Cloud migration is not just a storage upgrade. Cloud platforms provide a full stack of:
- Compute (virtual machines, containers, serverless)
- Storage (object, block, file)
- Networking
- Databases
- Security and identity
- Monitoring and automation
When done strategically, migration helps you move away from rigid, hardware-bound systems toward a more flexible, scalable IT environment.
Key Business Benefits of Moving to the Cloud
1. Cost Efficiency and Predictable Spend
Traditional on-premises infrastructure requires significant upfront capital expenditure:
- Servers and networking hardware
- Power, cooling, and racks
- Licences and maintenance
- Physical security and facilities
Cloud platforms switch this to an operational expenditure (OpEx) model. You typically:
- Pay only for what you use (pay-as-you-go)
- Scale up or down month to month
- Avoid large upfront investments and multi-year hardware cycles
With the right optimisation and governance, businesses often reduce their infrastructure costs by 30–50% compared to unmanaged legacy environments. The key is to plan capacity correctly and monitor usage so you’re not paying for idle resources.
2. Anywhere, Anytime Accessibility
One of the biggest advantages of cloud computing is access from anywhere with an internet connection. This is particularly powerful when:
- Your team works remotely or across multiple locations
- You have field or mobile workers
- You need to collaborate with partners, contractors, or clients
Cloud-hosted systems make it easier to support:
- Remote work and BYOD (Bring Your Own Device) policies
- Secure access to critical applications on laptops, tablets, and phones
- Collaboration tools like shared documents, video conferencing, and chat
With the right identity and access controls in place, your workforce can stay productive without being tied to a physical office or VPN-heavy experience.
3. Improved Flexibility and Agility
Cloud environments are inherently more agile than traditional infrastructure. You can:
- Spin up new servers in minutes instead of weeks
- Test new applications or features quickly
- Roll back changes faster if something doesn’t work
This agility allows IT to support the business more effectively. For example:
- A marketing team can launch a campaign microsite without waiting for new servers
- A development team can test new software builds in isolated environments
- A business unit can trial a new SaaS solution for a quarter, then scale or cancel easily
Overall, cloud migration helps your organisation respond faster to market changes, customer needs, and new opportunities.
4. Easy Scalability for Growing Businesses
On-premises infrastructure is typically sized based on peak demand, which means:
- Over-provisioning hardware “just in case”
- Long lead times to add capacity
- Under-utilised resources most of the year
Cloud platforms allow elastic scaling:
- Scale up resources during peak periods (e.g., EOFY, seasonal demand, big campaigns)
- Scale down during quieter periods
- Pay only for the resources you actually use
This is particularly valuable for:
- Growing businesses with uncertain demand
- Seasonal industries (retail, events, tourism, etc.)
- Organisations running data- or compute-heavy workloads only at certain times
5. Enhanced Security and Resilience
Well-designed cloud environments can offer:
- Multi-factor authentication (MFA) and strong identity management
- Encryption at rest and in transit
- Advanced threat detection and monitoring
- Built-in backup and disaster recovery options
- High availability across multiple regions and zones
Cloud migration, done properly, can reduce:
- Downtime from hardware failures
- Data loss risks
- Exposure to common cyberattacks (e.g. ransomware)
Of course, security is still a shared responsibility: the provider secures the platform, and your business must configure and manage it correctly. This is where expert guidance and managed services become crucial.
Cloud Service Models: IaaS, PaaS, and SaaS
Before planning a migration, it’s important to understand the three primary cloud service models. Each provides a different level of control and responsibility.
IaaS – Infrastructure as a Service
Infrastructure as a Service (IaaS) provides virtualised computing resources over the internet:
- Virtual machines (VMs)
- Storage
- Networking
You manage:
- Your operating systems
- Applications
- Data
- Security configurations within the VMs
The provider manages:
- Physical hardware
- Underlying network
- Data centre facilities
Examples:
- Amazon Web Services (AWS) EC2
- Microsoft Azure Virtual Machines
- Google Compute Engine
IaaS is ideal when you want flexibility and control but don’t want to manage physical infrastructure.
PaaS – Platform as a Service
Platform as a Service (PaaS) provides a complete platform for developing, running, and managing applications without dealing with the underlying infrastructure.
You manage:
- Application code and logic
- Data
The provider manages:
- Servers and OS
- Middleware and runtime
- Scaling and load balancing
Examples:
- Google App Engine
- Azure App Service
- AWS Elastic Beanstalk
SaaS – Software as a Service
Software as a Service (SaaS) delivers ready-to-use applications over the internet. You simply log in and start using the software.
You manage:
- User accounts and settings
- Your data inside the application
The provider manages everything else.
Examples:
- Microsoft 365 / Google Workspace
- Salesforce
- Xero
- Slack
SaaS is ideal when you want rapid deployment, predictable pricing, and minimal management overhead. Many cloud migration projects include a move from self-hosted applications to SaaS equivalents.
Cloud Deployment Models: Public, Private, Community, and Hybrid
Service models (IaaS, PaaS, SaaS) describe what you consume. Deployment models describe where and how your cloud is hosted.
Public Cloud
Public clouds are owned and operated by third-party providers. Your workloads run on shared infrastructure, but your resources are isolated from other customers.
Typical use cases:
- Application development and testing
- Websites and customer-facing apps
- File storage and backup
- Analytics and big data workloads
Advantages:
- No hardware to maintain
- High scalability and flexibility
- Pay-as-you-go pricing
Considerations:
- Data residency and compliance requirements
- Shared responsibility for security
- Reliance on internet connectivity
Examples: AWS, Microsoft Azure, Google Cloud Platform, IBM Cloud.
Private Cloud
A private cloud is dedicated to a single organisation. It may be:
- Hosted on-premises in your own data centre
- Hosted by a third-party provider but used only by your organisation
Advantages:
- Greater control over infrastructure
- Customisation to meet specific security or compliance requirements
- More predictable performance
Considerations:
- Higher upfront and ongoing costs
- Requires in-house or managed expertise
- Less elasticity than large public clouds
Community Cloud
A community cloud is shared by several organisations with similar needs, such as:
- Industry regulations
- Security requirements
- Shared projects or collaborations
The infrastructure and costs are shared between participants, making it more efficient than each organisation building its own private cloud.
Hybrid Cloud (and Multi-Cloud)
Example scenarios:
- Sensitive data stored in a private cloud; public cloud used for burst capacity
- Legacy systems remaining on-premises; new services built in the public cloud
- Disaster recovery using a secondary cloud environment
Many businesses also use multi-cloud, where different providers are used for different workloads (e.g. Azure for line-of-business apps, AWS for analytics, SaaS for CRM). Hybrid and multi-cloud approaches offer flexibility but require strong governance and integration planning.
The 5 R’s of Cloud Migration Strategies
There are several structured approaches to moving workloads to the cloud. One common framework is the 5 R’s of cloud migration:
1. Rehost (“Lift and Shift”)
Rehosting involves moving applications to the cloud with minimal or no changes.
- VMs from your data centre are replicated into cloud VMs
- Application architecture stays largely the same
Pros:
- Fastest and simplest to implement
- Lower upfront migration risk
- Good first step for organisations new to the cloud
Cons:
- May not fully leverage cloud capabilities
- Potential for higher ongoing costs if not optimised
2. Replatform (“Lift, Tinker, and Shift”)
Replatforming is similar to rehosting, but you make selected optimisations to benefit from cloud features:
- Moving from self-managed databases to managed database services
- Using cloud load balancers or managed storage
- Automating backups and scaling
Pros:
- Better performance and cost-efficiency than pure lift-and-shift
- Still relatively low risk and fast to deliver
Cons:
- Requires more planning and testing
- Some application changes may be necessary
3. Refactor (Re-architect)
Refactoring involves re-architecting applications to be cloud-native. This may include:
- Moving from monolithic applications to microservices
- Using containers and serverless functions
- Re-writing parts of the application to use cloud-native services
Pros:
- Maximum long-term benefits (scalability, resilience, speed)
- Significant potential for cost optimisation and innovation
Cons:
- Time-consuming and resource-intensive
- Requires deep technical expertise
- Higher short-term risk if not managed carefully
4. Rebuild
Rebuilding means starting over from scratch, designing a brand-new application that replaces the old one.
Typical reasons:
- The legacy application is too outdated or fragile
- The business has new requirements the old system can’t meet
- It’s more cost-effective to rebuild than to refactor
Pros:
- Complete freedom to design the ideal solution
- Opportunity to clean up technical debt and old processes
Cons:
- High cost and effort
- Requires strong change management and user training
5. Replace
Replace means retiring an existing application and adopting a new, usually SaaS-based, solution.
Examples:
- Replacing an on-premises CRM with Salesforce
- Moving from a legacy email server to Microsoft 365 or Google Workspace
Pros:
- Quick access to modern capabilities
- Reduced maintenance responsibility
- Often more predictable pricing
Cons:
- Data migration and integration work required
- Change management and user adoption challenges
- Some custom features may be lost or need re-implementation
In a real-world cloud migration, you’ll usually apply different R’s to different systems based on their value, complexity, and future role in the business.
Stages of a Cloud Migration Strategy
A successful cloud migration is not a single project; it’s a phased program. The typical stages include:
1. Define Business Objectives
Start with the why:
- Are you trying to reduce costs, improve performance, or enable remote work?
- Change managDo you need stronger security, better disaster recovery, or faster innovation?ement and user adoption challenges
- What business outcomes will define success (e.g. 30% cost reduction, faster time to market, less downtime)?
Clear objectives guide every technical decision that follows.
2. Assess Your Existing Environment
Perform a thorough discovery and assessment:
- Inventory applications, servers, databases, and integrations
- Identify dependencies between systems
- Evaluate performance, utilisation, and current pain points
- Assess security, compliance, and data residency requirements
This phase helps you:
- Decide which woDecide which workloads are cloud-readyrkloads are cloud-ready
- Prioritise migration waves
- Estimate costs and timelines
3. Select Cloud Providers and Service Models
Based on your objectives and assessment:
- Choose the primary cloud provider(s) that fit your requirements and budget
- Decide which workloads will use IaaS, PaaS, or SaaS
- Determine whether you need public, private, or hybrid deployments
Consider:
- Local data centres and data residency
- Compliance certifications
- Integration with existing tools (identity, security, monitoring, etc.)
- Support and managed service options
4. Design the Target Cloud Architecture
Create a detailed blueprint for your future environment:
- Network design (VPCs, subnets, connectivity to on-premises)
- Identity and access management (users, roles, MFA, SSO)
- Security controls (firewalls, encryption, monitoring)
- Backup and disaster recovery plans
- Logging, monitoring, and alerting
5. Plan Migration Waves
- Group applications and databases into logical migration waves
- Start with low-risk, high-value workloads to build confidence
- Plan cutover windows to minimise business disruption
- Document rollback plans in case something doesn’t go as expected
Not everything should move at once. Instead:
6. Choose Migration Tools and Methods
- Server and database replication
- Data transfer (online or offline, depending on volume and bandwidth)
- Application deployment and configuration management
- Testing and validation
Work with your cloud provider and IT partner to select the right tools for:
7. Execute the Migration
- Migrate applications and data according to your plan
- Perform functional, performance, and security testing
- Coordinate closely with business stakeholders for cutover and validation
- Monitor systems closely during and after go-live
During execution:
8. Optimise and Manage the New Environment
Once workloads are running in the cloud:
- Review resource usage and right-size services
- Implement cost monitoring and alerts
- Refine security controls based on real-world activity
- Update documentation and train staff on new processes
Cloud migration is the beginning of a continuous improvement cycle, not the final step.
Common Cloud Migration Challenges (and How to Avoid Them)
Even with good planning, cloud projects can run into problems. The most common include:
- Underestimated complexity – Hidden dependencies or legacy integrations can delay migrations.
- Unexpected costs – Over-provisioned resources, unused services, or excessive data transfer can inflate bills.
- Security gaps – Misconfigured access controls or storage can expose data.
- Performance issues – Poorly designed architectures can create latency or bottlenecks.
- User resistance – Staff may be reluctant to change tools or workflows.
Mitigation strategies:
- Invest time in discovery and dependency mapping
- Start small and iterate, rather than migrating everything at once
- Use tagging, budgets, and cost dashboards from day one
- Apply a security-first mindset to design and configuration
- Communicate early and often with users; provide training and support
The Role of Cloud Managed Services
Cloud providers such as AWS, Microsoft Azure, Google Cloud Platform, IBM Cloud, and Oracle Cloud offer powerful tools-but they don’t manage your environment for you.
Without the right skills and governance, it’s easy to:
- Misconfigure security settings
- Over-provision resources and overspend
- Miss out on new features and optimisations
Cloud managed service providers (MSPs) bridge this gap. They can:
- Assess your current environment and design a migration roadmap
- Implement best-practice architectures for security, performance, and cost
- Manage day-to-day operations, monitoring, and incident response
- Continuously optimise your environment as your business evolves
For many small and mid-sized businesses, partnering with a managed services provider is the most effective way to realise the full benefits of cloud migration without building a large in-house cloud team.
Need Help Planning or Executing Cloud Migration?
Jargon Buster (Quick Glossary)
- Cloud computing – Delivering computing services (servers, storage, databases, networking, software) over the internet instead of using local hardware.
- Cloud service provider – A company that offers cloud computing services on a pay-as-you-go or subscription basis (e.g. AWS, Azure, Google Cloud).
- Cloud managed services – Outsourced management and optimisation of your cloud environment, usually by a specialist IT provider.
- RoI (Return on Investment) – A measure of how much benefit (financial or otherwise) you gain compared to the cost of an investment.
- Legacy infrastructure – Outdated hardware or software that is still in use but is difficult to maintain, integrate, or modernise.
- IaaS / PaaS / SaaS – Cloud service models: Infrastructure, Platform, and Software as a Service.
- Hybrid cloud – A mix of on-premises, private, and public cloud environments working together.
- Multi-cloud – Using services from more than one public cloud provider.
FAQ
What is cloud migration in simple terms?
Cloud migration is the process of moving your data, applications, and IT systems from on-premises servers or legacy infrastructure to a cloud environment such as AWS, Microsoft Azure, or Google Cloud. In some cases, it can also mean moving between cloud providers or bringing selected workloads back on-premises.
How long does a typical cloud migration take?
The timeline depends on the size and complexity of your environment. A small business migrating a few applications might complete the project in a few weeks, while larger organisations with many interconnected systems may need several months or more. A proper assessment and phased plan help set realistic expectations.
Is moving to the cloud really more secure than on-premises?
When designed and managed correctly, cloud environments can be more secure than many on-premises setups. Leading cloud providers invest heavily in security, including encryption, access controls, and threat detection. However, security is a shared responsibility – you still need good configuration, policies, and ongoing monitoring.
How much does cloud migration cost?
Costs vary based on factors like the number of applications, data volume, provider choice, and whether you refactor or simply lift-and-shift. You’ll typically have short-term project costs (assessment, migration, testing) and ongoing operational costs (monthly cloud usage). Many businesses see savings over time through right-sizing and pay-as-you-go pricing.
Do we need a managed service provider for cloud migration?
You don’t have to use a managed service provider, but it’s often recommended – especially if you don’t have in-house cloud expertise. A good provider can help you plan the migration, avoid common pitfalls, optimise costs, and manage the environment after go-live so your internal team can focus on core business priorities.
