🎯 Migration Strategy Overview

Understanding the journey from on-premises to Azure cloud

📊 What is Cloud Migration?

Cloud migration is the process of moving digital business operations from on-premises infrastructure to cloud platforms. Think of it as moving from owning your own office building to renting modern, flexible workspace that scales with your needs.

🏗️ Migration Strategy Landscape

According to the Microsoft Cloud Adoption Framework, there are several migration strategies. This guide focuses on the two most common:

---
title: Azure Migration Strategy Decision Flow
---
flowchart TD
    A[🏢 Current Workload Assessment] --> B{🔍 Complexity & Requirements}
    
    B -->|Low complexity<br/>Quick migration needed| C[📦 REHOST Strategy]
    B -->|Medium complexity<br/>Some optimization desired| D[🔄 REFACTOR Strategy]
    B -->|High complexity<br/>Major transformation| E[🏗️ REARCHITECT Strategy]
    B -->|Legacy systems<br/>Completely new approach| F[🆕 REBUILD Strategy]
    
    C --> G[✅ Lift & Shift to IaaS]
    D --> H[🔧 Optimize for PaaS]
    E --> I[🏛️ Cloud-Native Design]
    F --> J[💻 New Development]
    
    G --> K[🎯 This Guide Covers]
    H --> K
    
    style K fill:#e1f5fe,stroke:#01579b,stroke-width:3px
    style C fill:#f3e5f5,stroke:#4a148c,stroke-width:2px
    style D fill:#e8f5e8,stroke:#1b5e20,stroke-width:2px

🎯 Focus: Rehost vs Refactor

📦 Rehost (Lift & Shift)

“Moving your applications to the cloud with minimal changes”

What it means in simple terms:

  • Like moving your furniture to a new house without changing the furniture itself
  • Applications run on Azure virtual machines instead of on-premises servers
  • Fastest path to cloud adoption
  • Minimal code changes required

Best for:

  • ✅ Legacy applications that work well as-is
  • ✅ Tight migration timelines
  • ✅ Limited cloud expertise initially
  • ✅ Regulatory requirements for infrastructure control

🔄 Refactor (Replatform)

“Optimizing applications to take advantage of cloud capabilities”

What it means in simple terms:

  • Like renovating your house to make it more energy-efficient and modern
  • Applications are modified to use cloud-native services
  • Better performance and cost optimization
  • Some code changes required

Best for:

  • ✅ Applications that can benefit from managed services
  • ✅ Cost optimization priorities
  • ✅ Performance improvement goals
  • ✅ Teams with cloud development skills

📈 Migration Strategy Comparison

Aspect 📦 Rehost 🔄 Refactor
⏱️ Time to Migrate 🟢 Fast (weeks) 🟡 Moderate (months)
💰 Initial Cost 🟢 Lower 🟡 Higher
🛠️ Complexity 🟢 Low 🟡 Medium
📊 Long-term Benefits 🟡 Limited 🟢 High
⚡ Performance Gains 🟡 Minimal 🟢 Significant
🔧 Maintenance 🔴 Higher 🟢 Lower
📈 Scalability 🟡 Manual 🟢 Automatic

🗺️ Migration Journey Phases 

---
title: Typical Migration Journey Timeline
---
flowchart LR
    subgraph Phase1 [📋 Phase 1: Assess & Plan]
        A1[🔍 Discovery] --> A2[📊 Assessment] --> A3[📋 Planning]
    end
    
    subgraph Phase2 [🏗️ Phase 2: Prepare]
        B1[☁️ Azure Setup] --> B2[🔐 Security] --> B3[🌐 Networking]
    end
    
    subgraph Phase3 [🚀 Phase 3: Migrate]
        C1[🧪 Pilot] --> C2[📦 Migrate] --> C3[✅ Validate]
    end
    
    subgraph Phase4 [⚡ Phase 4: Optimize]
        D1[📈 Monitor] --> D2[🔧 Optimize] --> D3[🏛️ Governance]
    end
    
    Phase1 --> Phase2 --> Phase3 --> Phase4
    
    style Phase1 fill:#e3f2fd,stroke:#1976d2
    style Phase2 fill:#f3e5f5,stroke:#7b1fa2
    style Phase3 fill:#e8f5e8,stroke:#388e3c
    style Phase4 fill:#fff3e0,stroke:#f57c00

🎯 Key Success Factors

🔍 Assessment is Critical

  • Inventory all applications and dependencies
  • Identify migration blockers early
  • Estimate costs for both strategies
  • Plan for downtime and user impact

👥 Team Readiness

  • Train teams on Azure fundamentals
  • Establish clear roles and responsibilities
  • Create communication plans for stakeholders
  • Set up support processes for post-migration

🛡️ Risk Management

  • Test thoroughly in non-production environments
  • Plan rollback strategies for each workload
  • Monitor performance before, during, and after migration
  • Document lessons learned for future migrations

📚 Framework Alignment

🏛️ Cloud Adoption Framework (CAF)

This guide aligns with CAF’s Adopt methodology:

  • ✅ Strategy: Business justification and expected outcomes
  • ✅ Plan: Migration approach and timeline
  • ✅ Ready: Landing zone and Azure setup
  • ✅ Adopt: Migration execution (this guide’s focus)

🏗️ Well-Architected Framework (WAF)

Every migration recommendation considers WAF pillars:

  • 🛡️ Security: Identity, encryption, network protection
  • 🔄 Reliability: Backup, disaster recovery, resilience
  • ⚡ Performance: Scalability, monitoring, optimization
  • 💰 Cost: Resource optimization, reserved instances
  • 🎯 Operational Excellence: Automation, governance, monitoring

🎯 Key Takeaways

  • 🎯 Choose the right strategy based on your timeline, complexity, and goals
  • 📦 Rehost is fastest but may limit long-term cloud benefits
  • 🔄 Refactor requires more effort but delivers better cloud-native advantages
  • 📋 Assessment and planning are critical for success regardless of strategy
  • 🏛️ Framework alignment ensures best practices and long-term success

📖 Next Steps: