SAP ECC to S/4HANA Conversion on Azure¶

Brownfield, greenfield, and selective data transition approaches for converting SAP ECC to S/4HANA on Azure infrastructure.

SAP ECC 6.0 mainstream maintenance ends December 31, 2027. A brownfield conversion for a mid-size enterprise typically takes 12--18 months. Starting after mid-2026 leaves no margin for dress rehearsals, testing, or unexpected issues. The time to begin is now.

Overview¶

S/4HANA conversion is not a database migration --- it is a functional transformation of the SAP system. Data models change (BSEG to ACDOCA, MATDOC replaces multiple material movement tables, business partner replaces customer/vendor master), custom code must adapt, and business processes may need re-validation. This guide covers the three conversion approaches and how Azure infrastructure supports each.

1. Conversion approaches compared¶

2. Brownfield conversion (system conversion)¶

2.1 Assessment phase¶

SAP Readiness Check¶

The SAP Readiness Check is a free SAP service that analyzes your ECC system and produces a detailed report on S/4HANA compatibility.

SAP Readiness Check Output:
├── Simplification Item Check
│   ├── Mandatory changes (must fix before conversion)
│   ├── Recommended changes (should fix)
│   └── Informational items
├── Custom Code Analysis
│   ├── Custom programs using deprecated APIs
│   ├── Custom programs affected by data model changes
│   └── Custom programs with hard-coded table references
├── Business Function Check
│   ├── Active business functions
│   └── S/4HANA compatibility of each function
├── Add-On Compatibility
│   ├── SAP add-ons installed
│   └── S/4HANA certified versions
└── Sizing Check
    ├── Current HANA memory usage
    └── Estimated S/4HANA HANA memory requirement

ABAP Test Cockpit (ATC)¶

" Run ATC checks against S/4HANA check variant
" Transaction: ATC
" Check Variant: S4HANA_READINESS_REMOTE or S4HANA_READINESS_2023

" Common findings:
" 1. SELECT on BSEG (replaced by ACDOCA in S/4HANA)
" 2. Direct access to MKPF/MSEG (replaced by MATDOC)
" 3. Customer/vendor master (KNA1/LFA1 → Business Partner)
" 4. Use of deprecated function modules
" 5. Hard-coded table names for removed/renamed tables

Custom code remediation effort estimation¶

Custom code remediation can begin before the S/4HANA conversion. Many changes (replacing deprecated function modules, using new APIs) are backward-compatible with ECC. Start remediation in your current ECC system to reduce the conversion-time workload.

2.2 Conversion execution with SUM¶

SUM (Software Update Manager) is the SAP tool that performs the system conversion. When combined with DMO (Database Migration Option), SUM can simultaneously convert the database to HANA and upgrade to S/4HANA.

SUM phases¶

Total downtime (typical): 24--48 hours for a 2 TB database with DMO.

SUM with DMO on Azure¶

# Target HANA VM is already deployed on Azure (see infrastructure-migration.md)
# SUM runs on the source system and connects to target HANA on Azure

# Key SUM parameters for Azure deployment
# MIGKEY=DMO_OPTION
# TARGET_HOST=<azure-hana-hostname>
# TARGET_INSTANCE=00
# TARGET_DB_TYPE=HDB  (HANA)
# SOURCE_DB_TYPE=ORA|DB6|MSS|ADA  (source database)
# MAX_PROCESSES=20  (parallelism for data migration)

# Start SUM
cd /usr/sap/<SID>/SUM
./STARTUP confighostagent
# Follow SUM GUI wizard

2.3 Data model changes in S/4HANA¶

Key data model changes that affect custom code and reports:

2.4 Downtime optimization¶

3. Greenfield implementation (new S/4HANA)¶

3.1 SAP Activate methodology¶

Greenfield S/4HANA implementations follow SAP Activate:

3.2 Deploy S/4HANA on Azure with ACSS¶

# Deploy S/4HANA using Azure Center for SAP Solutions
az workloads sap-virtual-instance create \
  --resource-group rg-sap-prod \
  --name S4H-PRD \
  --environment Production \
  --sap-product S4HANA \
  --location eastus2 \
  --configuration @sap-deployment-config.json

3.3 Data migration for greenfield¶

4. Selective data transition (shell conversion)¶

Selective data transition (also called "shell conversion" or "bluefield") combines elements of brownfield and greenfield. A new S/4HANA shell is deployed, and selected data is migrated from the source ECC system.

When to choose selective data transition¶

• You want a clean S/4HANA system but need specific historical data
• You are consolidating multiple ECC systems into one S/4HANA
• You want to archive old data while keeping recent transactions
• You need to restructure the organizational model (company codes, plants)

Tools for selective data transition¶

5. CSA-in-a-Box integration during conversion¶

During conversion: parallel analytics¶

While the S/4HANA conversion is in progress, CSA-in-a-Box can provide business continuity for analytics:

1. Extract from source ECC using ADF SAP Table connector
2. Build Fabric Lakehouse with ECC data in Delta tables
3. Create Power BI reports against Fabric data
4. Cut over analytics to Fabric Mirroring after S/4HANA go-live

After conversion: full integration¶

1. Configure Fabric Mirroring for S/4HANA HANA
2. Build dbt models against S/4HANA data model (ACDOCA, MATDOC, Business Partner)
3. Deploy Power BI semantic models for finance, supply chain, procurement
4. Enable Azure AI for process intelligence on S/4HANA data

6. Conversion timeline¶

gantt
    title ECC to S/4HANA Brownfield Conversion on Azure (18 months)
    dateFormat  YYYY-MM-DD
    section Assessment
    SAP Readiness Check                     :a1, 2026-07-01, 3w
    Custom code analysis (ATC)              :a2, after a1, 4w
    section Infrastructure
    Azure landing zone + ACSS deploy        :a3, 2026-07-01, 6w
    HANA installation + HA config           :a4, after a3, 4w
    section Remediation
    Custom code remediation (parallel)      :a5, after a2, 24w
    S/4HANA sandbox testing                 :a6, after a4, 12w
    section Conversion
    SUM/DMO dress rehearsal 1               :a7, after a6, 3w
    SUM/DMO dress rehearsal 2               :a8, after a7, 3w
    SUM/DMO production conversion           :a9, after a8, 2w
    section Post-Conversion
    Functional testing                      :a10, after a9, 4w
    Performance testing                     :a11, after a10, 3w
    section Analytics
    Fabric Mirroring + Power BI             :a12, after a9, 6w
    Azure AI integration                    :a13, after a12, 4w
    section Go-Live
    Hypercare + optimization                :a14, after a11, 8w

6. Post-conversion validation checklist¶

After S/4HANA conversion, systematically validate every functional area before go-live.

Technical validation¶

Functional validation (by module)¶

S/4HANA-specific validation¶

7. Common issues and troubleshooting¶

8. Risk mitigation strategies¶

Last updated: 2026-04-30 Maintainers: CSA-in-a-Box core team Related: HANA Migration | Infrastructure Migration | Feature Mapping