How Do You Plan a Cloud Migration Strategy? The 7 Rs, Sequencing and Cost Control

The short answer

A good cloud migration strategy is a portfolio decision, not a single move: you decide a treatment for each application using the 7 Rs, sequence the work in waves by risk and value, and build cost and security controls before the first workload moves. Organisations that 'lift and shift' everything without that analysis often end up paying more for the same problems in a new location.

Why are you moving to the cloud?

Start here, because the answer shapes everything else. Common, legitimate reasons include:

• A data centre lease, hosting contract or hardware refresh is approaching
• The business needs to scale up and down quickly
• Resilience and disaster recovery are weak on-premises
• Teams want modern managed services rather than maintaining servers
• Legacy applications are being replaced by software-as-a-service products anyway

'Everyone else is doing it' is not a reason. Write down two or three measurable goals, such as exiting a hosting facility by a set date or improving recovery time for critical systems, and use them to test every later decision.

Build an application and dependency inventory

You cannot plan what you cannot see. For each application or workload, capture:

• Business owner and criticality
• Users, data sensitivity and any data residency obligations
• Technical stack, licensing and support status
• Dependencies on other systems, databases and integrations
• Current running cost and planned changes

Dependencies are the part most often missed. A finance system that quietly reads from a reporting database, which in turn feeds a warehouse application, needs to move as a group or be carefully re-connected.

Use the 7 Rs to decide each application's treatment

Retire and repurchase are frequently underused. Every application retired is one you never pay to migrate, secure or run again. Where an application is a candidate for replacement, our guide on whether to replace or modernise a legacy system helps frame the choice.

Build the foundations first

Before migrating workloads, establish a landing zone: the shared foundation of identity, network design, security controls, logging, backup and cost management. Key decisions include:

1. How accounts or subscriptions are structured, for example by environment or business unit
2. How identity and privileged access are managed
3. Which security baselines and monitoring apply by default
4. How backup and disaster recovery work in the new environment
5. How every resource is tagged with an owner and cost centre

Skipping this step usually means each project invents its own setup, creating security gaps and costs that nobody can attribute. Security governance should be part of the design from the start; see our cybersecurity governance service.

Sequence the migration in waves

Group applications into waves based on dependencies, risk and business value:

• Wave 0, pilot: development and test environments or simple internal tools. The aim is to prove the landing zone, tooling and runbooks.
• Wave 1, low risk: standalone applications with few dependencies.
• Wave 2, business systems: grouped applications that share data, moved together.
• Wave 3, critical systems: core platforms, moved once the team has repeatable processes and confidence.

Avoid scheduling critical cutovers near peak trading periods or end of financial year. Each wave should finish with a short review: what went wrong, what cost more than expected, and what to change before the next one.

How do you control cloud costs?

Cloud spend behaves very differently from capital hardware. It is easy to start, easy to grow and easy to forget. Build financial operations (often called FinOps) into the programme:

• Tag everything with an owner, environment and cost centre
• Set budgets and alerts per account or project
• Rightsize after migration, using actual utilisation rather than old server specifications
• Schedule non-production environments to shut down outside business hours
• Commit wisely: reserved capacity or savings plans only once usage is stable
• Review monthly, with business owners accountable for their spend

A practical example: a test environment rehosted with the same specification as the old physical servers and left running around the clock can cost far more than it needs to. Scheduling and rightsizing it is often one of the quickest savings available. Our IT cost optimisation service and our guide to reducing IT costs cover this in more depth.

Common cloud migration mistakes

• Migrating everything the same way because it is simpler to plan
• Underestimating dependencies and data transfer
• Treating licensing as an afterthought, particularly for databases and operating systems
• Leaving old infrastructure running long after cutover
• Assuming the cloud provider handles security and backup by default

How The Technology Office leads cloud migrations

The Technology Office provides independent, owner-side leadership for cloud migrations as part of our technology and systems transformation service. Because we sell no hosting, licences or migration services and take no implementation margin, our advice on what to move, what to retire and what to replace is driven solely by your outcomes and costs.

We set goals and decision gates before engaging providers, build cost control in from day one, and hold partners accountable for each wave. We work with businesses of any size and industry across Australia.