Google Cloud Migration Planning: A Practical Readiness Guide

Start with the reason and a definition of success

Organizations move to Google Cloud for different reasons: hardware reaching end of support, leaving a data center, using analytics and AI services, scaling for growth or improving disaster recovery. The reason shapes the plan. A hardware deadline favors moving quickly with few changes; an analytics strategy may justify re-architecting.

Agree what success means before any work starts: application performance for users, recovery objectives, a cost range, required security controls and a timeline. Without agreed criteria, the cutover weekend turns into a debate.

Phase 1: Assess what you have

• Inventory. List servers, virtual machines, databases, storage and applications. Google's Migration Center can collect inventory and utilization data to speed this up.
• Dependencies. Record which systems call which, scheduled jobs, file shares, printers and integrations with partners and banks.
• Performance baselines. Capture CPU, memory, disk and network use over a representative period that includes month-end or seasonal peaks.
• Data. Measure volumes and change rates. They decide the transfer method and how long synchronization takes.
• Licensing. Some commercial software has specific rules for cloud hosting or requires sole-tenant nodes. Check before you plan.
• Obligations. Note data residency, contractual and sector requirements for each workload.
• Skills. Be honest about what the team can operate after migration.

The output is a catalogue with an owner, criticality, dependencies and a proposed approach for every workload.

Choosing an approach for each workload

Phase 2: Plan the foundation

• Resource hierarchy. Organization, folders by environment or business unit, and separate projects per application and environment.
• Identity. Cloud Identity or Google Workspace, federated with Microsoft Entra ID if that is your directory. Grant IAM roles to groups, not individuals, and enforce 2-Step Verification.
• Service accounts. Avoid downloadable keys. Use attached service accounts and workload identity federation.
• Networking. Shared VPC or hub-and-spoke, non-overlapping IP ranges, Cloud VPN or Cloud Interconnect to your sites, Cloud NAT and firewall policies.
• Security. Organization policies (for example, restricting external IP addresses and resource locations), Cloud Audit Logs with defined retention and Security Command Center.
• Billing. Budgets and alerts, labels for cost allocation and billing export to BigQuery for analysis.

Google's enterprise foundations blueprint documents a complete reference design. Smaller organizations can adopt a subset, but should make each decision consciously.

Region selection and latency

Measure latency from your offices and customers to candidate regions, confirm that each region offers the services you need, and compare prices. Interactive applications used from Philippine offices are more sensitive to region choice than batch or analytics workloads.

Wave planning

• Group workloads that depend on each other into the same wave.
• Start with a low-risk pilot that still exercises the foundation: identity, networking, monitoring and backup.
• Schedule waves around the business calendar, avoiding month-end close, payroll and peak seasons.
• Give every wave a pre-migration checklist, data synchronization plan, test plan, cutover runbook and a short hypercare period.

Phase 3: Deploy, test and cut over

• Functional tests with the business users who know the application.
• Performance tests compared with the baseline from assessment.
• Security checks: access, firewall rules and exposed services.
• A backup and restore test in the new environment.
• DNS time-to-live values lowered a few days before cutover.
• A cutover runbook with timings, a go/no-go decision point and rollback criteria.
• Communication to users before, during and after.

Phase 4: Optimize

• Apply rightsizing recommendations after a few weeks of real usage.
• Consider committed use discounts once usage is stable.
• Set storage lifecycle rules and review logging volumes.
• Decommission the old systems and securely wipe their disks.

Readiness checklist

• Business case and success criteria agreed.
• Inventory with owners, dependencies and baselines complete.
• Migration approach chosen for every workload.
• Licensing and data obligations reviewed.
• Foundation designed and built: hierarchy, identity, network, security, billing.
• Connectivity to on-premises tested.
• Waves planned around the business calendar.
• Test plans, runbooks and rollback criteria written.
• Operations model agreed: monitoring, patching, backup, support.