Moving to the cloud is no longer a question of if but when and how. Yet for every success story, there is a cautionary tale of missed timelines, ballooning costs, and outages that could have been avoided with better planning. This guide cuts through the complexity to give you a repeatable framework.
Why Migrations Fail
Most cloud migrations that go over budget share common root causes: underestimating dependencies between services, skipping the discovery phase, and treating migration as a purely technical exercise rather than an organisational change programme.
Phase 1 — Discovery & Assessment
Before moving a single byte, conduct a comprehensive audit of your existing infrastructure. Map every application, its dependencies, its owners, and its criticality to the business.
- Inventory all servers, databases, and third-party integrations.
- Classify workloads by sensitivity (PII, financial data, regulated).
- Identify quick wins (stateless apps) versus complex migrations (stateful databases).
- Set clear SLAs for uptime during the migration window.
Phase 2 — Choosing the Right Strategy
Gartner's classic 5 Rs remain the best mental model for planning each workload's journey:
- Rehost (Lift & Shift): Fastest, lowest risk, minimal cloud benefit.
- Replatform: Small optimisations without changing core architecture.
- Repurchase: Switch to a SaaS equivalent.
- Refactor: Re-architect for cloud-native patterns — highest value, highest effort.
- Retire: Decommission workloads that no longer serve a business purpose.
Phase 3 — Execution & Validation
Migrate in waves, starting with non-critical workloads. Establish rigorous rollback procedures before each wave. Use blue-green deployments to maintain business continuity and validate performance benchmarks against your on-prem baselines before cutting over production traffic.
Key Metrics to Track
Define success before you start. Useful migration KPIs include time-to-restore, cost per workload, deployment frequency post-migration, and critical path latency.
KEY INSIGHT "The goal is not to have your applications in the cloud — it is to have your business powered by cloud-native capabilities."
A structured, phased approach transforms a daunting project into a series of manageable milestones. Take the time to plan thoroughly, and the maze becomes a well-marked path.