Migration of SAP ECC from AWS to Azure with S/4HANA Transformation

Summary

A global enterprise running SAP ECC on AWS aimed to modernize its ERP platform by migrating to SAP S/4HANA while also transitioning to Microsoft Azure. Using Azure Migrate, the organization executed a phased migration strategy, ensuring minimal downtime, optimized cost, and reduced risk.

Business Objectives

Primary Goals:

• Exit AWS and standardize on Azure
• Upgrade from ECC → S/4HANA
• Improve performance using SAP HANA
• Reduce infrastructure cost
• Enable future cloud-native innovation

Key Challenges

• SAP is tightly coupled (high dependency risk)
• Large database size (multi-terabyte)
• Downtime constraints (business-critical workloads)
• Licensing and compatibility concerns
• Dual transformation (cloud + platform)

Strategy Chosen

Two-Phase Approach

| Phase | Description | | ——- | ——————————- | | Phase 1 | Rehost SAP ECC from AWS → Azure | | Phase 2 | Convert ECC → S/4HANA |

Why this strategy?

• Reduces migration complexity
• Enables better testing
• Provides rollback capability
• Separates infrastructure and application risks

Migration Architecture (Conceptual)

Source (AWS):

• SAP ECC App Servers
• Database Server
• Integrated systems (CRM, BW, Interfaces)

Target (Azure):

• Azure Virtual Machines
• SAP-certified VM sizes
• High-performance storage
• Secure VNet with subnets

Migration Execution (Step-by-Step)

Step 1: Discovery

Action: Inventory all SAP components using Azure tools Tool: Azure Migrate Outcome:

• Identified:
  • App servers
  • DB servers
  • Interfaces

Why this step: Missing even one SAP dependency can break the system post-migration

Step 2: Assessment

Action:

• Analyze performance metrics:
  • CPU
  • Memory
  • Disk I/O

Output:

• Azure VM sizing recommendations
• Cost estimation

Why: Prevents over-provisioning and ensures SAP workloads perform efficiently in Azure

Step 3: Dependency Mapping

Action:

• Identify communication between SAP systems and external applications

Outcome:

• Grouped servers into logical migration waves

Why: SAP systems must be migrated as a unit to avoid functional failures

Step 4: Azure Landing Zone Setup

Action:

• Configure:
  • Virtual Network (VNet)
  • Subnets (App, DB)
  • Network Security Groups
  • VPN / ExpressRoute

Why: SAP requires low latency, secure, and highly available infrastructure

Step 5: Replication Setup

Tool: Azure Migrate: Server Migration

Action:

• Enable continuous replication from AWS → Azure

Why: Keeps Azure environment in sync and minimizes downtime

Step 6: Test Migration

Action:

• Launch test SAP system in Azure

Validation:

• System boot
• SAP services
• Network connectivity

Why: Ensures system works before final cutover without impacting production

7: Cutover

Action:

• Stop SAP in AWS
• Perform final data sync
• Start SAP in Azure

Outcome:

• Successful migration with controlled downtime

Why: This is the only downtime window; must be planned carefully

Phase 2: S/4HANA Conversion

Step 8: Preparation

Action:

• Data cleanup
• Code adaptation
• Compatibility checks

Why: S/4HANA has stricter requirements than ECC

Step 9: Database Migration

Action:

• Move database → SAP HANA

Tool:

• SAP Software Update Manager (SUM)

Why: S/4HANA only runs on HANA

Step 10: Testing

Types:

• Functional testing
• Performance testing
• User Acceptance Testing

Why: SAP impacts core business operations

Post-Migration Optimization

Actions:

• Right-size Azure VMs
• Implement Reserved Instances
• Enable monitoring and alerts
• Configure backup & disaster recovery

Why: Ensures cost efficiency and system reliability

Risks & Mitigation

| Risk | Mitigation | | ——————– | ——————————— | | Downtime | Use replication + planned cutover | | Data inconsistency | Validation checks | | Performance issues | Proper sizing | | Integration failures | Dependency mapping |

Key Learnings (What you say in interviews)

• Separating infrastructure migration from application transformation reduces risk.
• Dependency mapping is critical for SAP workloads.
• Test migration is essential before cutover.
• Optimization after migration is as important as migration itself.