Thinking about moving your infrastructure to the cloud? Great idea, but keep in mind that many companies experience unexpected challenges during migration or exceed their initial budget.
To avoid that, you need a solid cloud migration plan (preferably combined with quality cloud migration services from a knowledgable contractor).
A cloud migration plan is your tactical blueprint for moving workloads from their current location (on-premises data centers, colocation facilities, or other cloud providers) to your target cloud platform. It’s the operational plan that answers: which systems move when, how they move, who does what, and what happens if things go sideways.
Before You Start: The Cloud Migration Checklist
Rushing into cloud migration can be expensive. Not having a solid plan will make it even more costly. Companies that skip proper planning typically overspend by roughly 75%. Think through these points before you begin:
☐ Start by assessing your current infrastructure comprehensively. Document every server, application, database, and service. Use tools like Azure Migrate or AWS Application Discovery Service to automate discovery.
☐ Map all dependencies between systems before you do anything else. Every application connects to something:databases, APIs, authentication services, shared storage. Missing dependencies cause outages. Tools like Azure Migrate create visual dependency maps that identify connections you didn’t know existed.
☐ Identify business constraints and blackout periods upfront. Financial close periods, product launches, holiday shopping seasons are migration no-go zones. Document these constraints and build your timeline around them. Add buffer time because schedules always slip.
☐ Evaluate your team’s cloud skills honestly. Does your team know Azure networking, cloud security models, and infrastructure-as-code? Skills gaps torpedo migrations. Invest in training or bring in cloud migration as a service expertise before you need it mid-crisis.
☐ Calculate realistic cloud costs using actual usage patterns. Cloud pricing is complex. Include data transfer costs—egress charges add up fast—plus backup storage and the hidden costs of split-environment operations during migration.
☐ Define success criteria and metrics before migration starts. What does success look like? Uptime targets? Performance benchmarks? Cost targets? Document measurable criteria so you can objectively evaluate results.
It feels slow, but it prevents the expensive mistakes that derail migrations.
The Cloud Migration Process
Let’s break down the cloud migration process into phases.
Discovery and Assessment (2-4 weeks)
Map your current state using automated discovery tools to create a complete inventory. Capture technical specifications, current utilization, and performance baselines. This data drives right-sizing decisions in the cloud.
Analyze dependencies and group tightly coupled systems together so that they migrate as units.
Classify workloads by complexity and risk. Tag each workload as low, medium, or high complexity based on architecture, dependencies, and business criticality. High-risk systems need more planning, testing, and safeguards.
Calculate migration costs using real numbers for compute, storage, networking, and data transfer. Include migration tooling costs, temporary infrastructure for parallel running, and potential consulting support.
Migration Planning (3-6 weeks)
Determine your data migration path first. ExpressRoute provides private, dedicated connections that are faster and more secure. VPN creates an encrypted tunnel when you need secure transfer but don’t have ExpressRoute. Azure Data Box works for offline migrations with large datasets—Microsoft ships you a physical device. Public internet works when data doesn’t need encryption, but it’s the least secure option.
Then sequence your workloads into migration waves strategically. Start with low-risk, low-complexity systems. Include one representative complex workload per wave to expose challenges early. Move non-production environments before production. Group interdependent systems in the same wave.
Select migration methods per workload. Downtime migration means shutting down the source, migrating data, then starting the target. It’s faster and simpler but requires service interruption. Near-zero downtime migration uses continuous replication with a final cutover which is essential for customer-facing applications and systems with strict SLAs.
Create detailed runbooks for each workload. Document step-by-step procedures including pre-migration tasks, cutover steps, validation criteria, and post-migration optimization. Your runbook should be detailed enough that someone else could execute it.
Define rollback procedures before you need them. Document rollback criteria that specify what conditions trigger a rollback. Define rollback steps that explain exactly how to revert. Test these procedures in non-production environments first.
Environment Preparation (2-4 weeks)
Set up cloud networking first. Configure virtual networks, subnets, network security groups, and connectivity to on-premises environments. Establish ExpressRoute or VPN connections and validate connectivity thoroughly.
Implement identity and access management before any workloads migrate. Connect Azure AD or AWS IAM to existing identity systems. Configure role-based access control and implement multi-factor authentication.
Deploy monitoring and management tools before migrating workloads. Set up Azure Monitor, Log Analytics, or equivalent services. Configure alerts for critical metrics and establish dashboards for ongoing operational oversight.
Migration Execution
Start with pilot migrations using 2-3 low-risk workloads. Execute the full migration process, validate thoroughly, and gather lessons learned. Use these learnings to refine runbooks and processes before tackling more critical systems.
Execute migrations wave by wave following your sequencing plan, but remain flexible. Technical issues, business constraints, or resource availability will force adjustments. Maintain clear communication about schedule changes and impacts.
Validate extensively after each migration. Validate functionality, performance, integrations, and user experience. Run automated tests, conduct user acceptance testing, and monitor carefully for the first 48-72 hours post-migration.
Optimization and Decommissioning
Right-size resources based on actual usage after 30-60 days of production operation. Initial migrations often overprovision resources for safety. After you have real production usage data, analyze actual utilization and adjust.
Implement cloud-native features to replace traditional high-availability approaches. Use managed databases, implement auto-scaling, leverage platform services like Azure Functions or Lambda. These changes reduce operational overhead and improve resilience.
Decommission source infrastructure once workloads run successfully in cloud for 60-90 days. This is when cost savings materialize. Document what’s decommissioned, archive necessary data, and reclaim data center space.
Common Mistakes in Cloud Migration Planning
Avoid these to save costs:
- Underestimating dependency complexity is the number one planning failure. Applications rarely operate in isolation. Missing a single dependency during migration causes outages and delays. Use automated dependency mapping tools and validate findings manually.
- Skipping non-production environment migrations costs time and money. Always migrate dev and staging environments first to validate your approach. The time spent on non-production migrations is tiny compared to fixing production problems.
- Ignoring application architecture leads to failed migrations. Legacy applications with hard-coded IP addresses, licensing tied to hardware, or outdated dependencies require re-architecture before migration. Identify these applications during assessment and plan accordingly.
- Inadequate rollback planning leaves teams scrambling when migrations fail. Every migration should have clear rollback procedures tested in advance. Define exactly what triggers a rollback, who makes that decision, and how to revert to the source environment.
Let’s Talk About Your Cloud Migration
And if you’re looking at your infrastructure and thinking “we need to move to cloud, but this is more complex than we thought”, let’s talk. We’ve helped companies across industries execute successful cloud migrations with little to no operational disruptions.
Our approach focuses on sustainable success: not just getting workloads into the cloud, but ensuring your team can operate and optimize them long-term.
