On-Prem to Azure Migration Program Playbook
A phased program to migrate an on-premises estate to Azure: assessment and business case, Azure landing zone, wave migration with replatforming, and optimize-and-govern with on-prem decommission.
On-Prem to Azure Migration Program Playbook
Migrating an on-premises estate to Microsoft Azure is a common enterprise journey, often eased by Microsoft licensing benefits like Azure Hybrid Benefit. This program assesses the estate, builds an Azure foundation, migrates in waves, and optimizes for cost and governance.
Phase-by-Phase
Assess and Plan. Discover the full estate with dependency mapping, assign a disposition from the 7 Rs to each workload, and build a business case that quantifies savings including Hybrid Benefit and reserved capacity. Discovery quality determines program success.
Azure Foundation. Deploy a landing zone with management groups, Azure Policy, and hub-spoke networking. Establish ExpressRoute for reliable hybrid connectivity, and configure Entra ID for unified identity during coexistence.
Migration Waves. Migrate servers and data in dependency-grouped waves using Azure Migrate for rehosting and replication. Replatform the workloads that justify it, for example moving SQL Server to Azure SQL or apps to AKS. Keep tested rollbacks through every cutover.
Optimize and Govern. Right-size running workloads, apply reservations and Hybrid Benefit to cut cost, enforce governance through Azure Policy, and decommission the on-prem estate to capture the savings.
Team and Roles
An architect owns dispositions and the landing zone. DevOps and SRE run migration. DBAs own data migration. Security owns identity and governance. Product owners accept cutovers.
Risks and Mitigations
Incomplete discovery causes mid-migration surprises; use automated dependency discovery. The data transfer window is mitigated with replication and, for large datasets, offline transfer appliances. Missed license optimization wastes money; model Hybrid Benefit explicitly. Dual-running cost is mitigated by decommissioning promptly after each wave stabilizes.
Success Criteria
All in-scope workloads run on Azure, run-rate cost drops, downtime stays within target, and the on-prem estate is decommissioned.
Tooling
Terraform or Bicep provisions the landing zone, Azure Migrate handles rehosting, AKS (Kubernetes) runs replatformed apps, PostgreSQL and Azure SQL hold migrated data, Grafana visualizes Azure Monitor, and Vault or Key Vault manages secrets.