sap-migration

# SAP Migration — Data Migration & System Conversion ## Related Skills - `sap-s4hana-extensibility` — Custom objects to migrate in S/4HANA - `sap-testing-quality` — Migration testing and data validation - `sap-cloud-alm` — Migration project management and tracking - `sap-abap-advanced` — Classic ABAP → ABAP Cloud code migration - `sap-devops-cicd` — Transport management during migration cutover ## Quick Start **Choose your migration scenario:** | Scenario | Approach | Key Tool | |----------|----------|----------| | **New Implementation (Greenfield)** | Fresh S/4HANA, migrate master/transactional data | Migration Cockpit (LTMC) | | **System Conversion (Brownfield)** | Convert existing ECC to S/4HANA in-place | SUM (Software Update Manager) | | **Selective Data Transition** | Mix of new + migrated data | SAP Data Services / SNP CrystalBridge | | **Cloud Migration** | On-premise → S/4HANA Cloud | Migration Cockpit Cloud | **Migration Cockpit Quick Start:** 1. Transaction `LTMC` → Create Migration Project 2. Select Migration Object (e.g., "General Ledger Account") 3. Download XML template → Fill with source data 4. Upload → Validate → Simulate → Execute ## Core Concepts ### Migration Phases ``` Assessment ──► Preparation ──► Realization ──► Testing ──► Cutover ──► Hypercare │ │ │ │ │ │ Scope & Data Build & Validate Go-live Monitor Mapping Cleansing Configure & UAT Execute & Fix ``` ### Migration Tools Landscape | Tool | Use Case | Data Volume | Complexity | |------|----------|-------------|------------| | **LTMC (Migration Cockpit)** | Standard objects, file upload | Medium | Low | | **LTMOM (Migration Object Modeler)** | Custom migration objects | Medium | Medium | | **SAP Data Services** | Complex ETL, large volumes | High | High | | **LSMW** | Legacy (ECC), batch input/IDoc/BAPI | Medium | Medium | | **Custom ABAP Programs** | Non-standard scenarios | Any | High | | **SAP Signavio (Process)** | Process migration planning | N/A | Medium | | **SUM** | System conversion (brownfield) | All | Very High | ### Standard Migration Objects (LTMC) | Domain | Key Objects | |--------|------------| | **Finance** | GL Account, Cost Center, Profit Center, Customer, Vendor, Open Items | | **Materials** | Material Master, BOM, Routing, Batch, Serial Number | | **Sales** | Sales Order, Pricing, Customer-Material Info Record | | **Procurement** | Purchase Order, Source List, Quota Arrangement, Contract | | **Plant Maintenance** | Equipment, Functional Location, Maintenance Plan | | **HR/HCM** | Employee Master, Org Structure, Time Data, Payroll Results | | **Asset Accounting** | Asset Master, Asset Values, Depreciation Areas | ### Data Migration Architecture ``` Source System ──► Extract ──► Transform ──► Load ──► Validate │ │ │ │ │ ECC/Legacy SAP DS / Mapping & LTMC / Reconcile Flat files Custom ABAP Cleansing BAPI Reports 3rd party RFC/DB Rules Staging ``` ## Common Patterns ### Pattern 1: Migration Cockpit — File-Based Migration ```xml <!-- Template structure for Material Master migration --> <!-- Download from LTMC, fill, re-upload --> <MigrationObject name="Material"> <HeaderData> <MATNR>MAT-001</MATNR> <MAKTX>Laptop Computer 15 inch</MAKTX> <MTART>FERT</MTART> <!-- Material Type --> <MBRSH>M</MBRSH> <!-- Industry Sector --> <MEINS>EA</MEINS> <!-- Base UoM --> <MATKL>001</MATKL> <!-- Material Group --> <SPART>01</SPART> <!-- Division --> <BISMT>OLD-MAT-001</BISMT> <!-- Old Material Number --> </HeaderData> <PlantData> <WERKS>1010</WERKS> <EKGRP>001</EKGRP> <!-- Purchasing Group --> <DISMM>PD</DISMM> <!-- MRP Type --> <DISPO>001</DISPO> <!-- MRP Controller --> <PLIFZ>5</PLIFZ> <!-- Planned Delivery Time --> </PlantData> <StorageLocationData> <WERKS>1010</WERKS> <LGORT>0001</LGORT> </StorageLocationData> <SalesData> <VKORG>1010</VKORG> <VTWEG>10</VTWEG> <SPART>01</SPART> </SalesData> </MigrationObject> ``` ### Pattern 2: Custom Migration Object (LTMOM) ```abap " Step 1: Create custom migration object in LTMOM " Step 2: Implement BAPI/staging table approach " Migration class for custom object CLASS zcl_migrate_custom_obj DEFINITION. PUBLIC SECTION. METHODS: validate_data IMPORTING it_data TYPE ztab_migration_data RETURNING VALUE(rt_errors) TYPE bapiret2_t, execute_migration IMPORTING it_data TYPE ztab_migration_data RETURNING VALUE(rt_results) TYPE ztab_migration_result. ENDCLASS. CLASS zcl_migrate_custom_obj IMPLEMENTATION. METHOD validate_data. LOOP AT it_data ASSIGNING FIELD-SYMBOL(<data>). " Mandatory field checks IF <data>-field1 IS INITIAL. APPEND VALUE #( type = 'E' id = 'ZMIG' number = '001' message_v1 = <data>-key_field message = |Field1 is mandatory for { <data>-key_field }| ) TO rt_errors. ENDIF. " Value mapping check IF NOT check_value_mapping( <data>-old_value ). APPEND VALUE #( type = 'E' id = 'ZMIG' number = '002' message = |No mapping for value { <data>-old_value }| ) TO rt_errors. ENDIF. ENDLOOP. ENDMETHOD. METHOD execute_migration. LOOP AT it_data ASSIGNING FIELD-SYMBOL(<data>). TRY. " Call BAPI or direct insert CALL FUNCTION 'BAPI_CUSTOM_CREATE' EXPORTING is_header = map_to_target( <data> ) IMPORTING ev_number = DATA(lv_number) TABLES return = DATA(lt_return). READ TABLE lt_return WITH KEY type = 'E' TRANSPORTING NO FIELDS. IF sy-subrc = 0. CALL FUNCTION 'BAPI_TRANSACTION_ROLLBACK'. APPEND VALUE #( key = <data>-key_field status = 'E' messages = lt_return ) TO rt_results. ELSE. CALL FUNCTION 'BAPI_TRANSACTION_COMMIT' EXPORTING wait = abap_true. APPEND VALUE #( key = <data>-key_field status = 'S' new_number = lv_number ) TO rt_results. ENDIF. CATCH cx_root INTO DATA(lx_error). APPEND VALUE #( key = <data>-key_field status = 'E' message = lx_error->get_text( ) ) TO rt_results. ENDTRY. ENDLOOP. ENDMETHOD. ENDCLASS. ``` ### Pattern 3: Value Mapping Table ```abap " Value mapping for legacy → S/4HANA conversion " Store in custom table ZTAB_VALUE_MAP TYPES: BEGIN OF ty_value_map, object_type TYPE char20, " e.g., MATERIAL_TYPE source_value TYPE char50, " Legacy value target_value TYPE char50, " S/4HANA value valid_from TYPE datum, valid_to TYPE datum, END OF ty_value_map. " Usage in migration METHOD map_value. SELECT SINGLE target_value FROM ztab_value_map WHERE object_type = @iv_object_type AND source_value = @iv_source_value AND valid_from <= @sy-datum AND valid_to >= @sy-datum INTO @rv_target_value. IF sy-subrc <> 0. " No mapping found — log warning and use source value log_warning( |No mapping: { iv_object_type }/{ iv_source_value }| ). rv_target_value = iv_source_value. ENDIF. ENDMETHOD. ``` ### Pattern 4: Data Quality Report ```sql -- Pre-migration data quality checks (run on source ECC) -- Duplicate customer check SELECT kunnr, name1, COUNT(*) AS cnt FROM kna1 GROUP BY kunnr, name1 HAVING COUNT(*) > 1; -- Orphan records (sales orders without customer) SELECT vbak~vbeln, vbak~kunnr FROM vbak LEFT OUTER JOIN kna1 ON vbak~kunnr = kna1~kunnr WHERE kna1~kunnr IS NULL; -- Material without valid UoM SELECT matnr, meins FROM mara WHERE meins NOT IN (SELECT msehi FROM t006); -- Open items with missing clearing info SELECT bukrs, belnr, gjahr, buzei, dmbtr FROM bsid -- Open customer items WHERE augdt IS NULL AND budat < '20200101'; -- Very old open items -- Vendor/Customer with incomplete address SELECT lifnr, name1, stras, ort01, pstlz, land1 FROM lfa1 WHERE stras IS INITIAL OR ort01 IS INITIAL OR land1 IS INITIAL; ``` ### Pattern 5: Reconciliation Report ```abap " Post-migration reconciliation REPORT z_migration_reconcile. " Compare source vs target record counts TYPES: BEGIN OF ty_recon, object_name TYPE char30, source_count TYPE i, target_count TYPE i, difference TYPE i, status TYPE char10, END OF ty_recon. DATA: lt_recon TYPE TABLE OF ty_recon. " Material Master SELECT COUNT(*) FROM mara INTO @DATA(lv_target_mat). " Source count from migration log SELECT source_count FROM zmig_log WHERE object = 'MATERIAL' AND run_id = @p_run_id INTO @DATA(lv_source_mat). APPEND VALUE #( object_name = 'Material Master' source_count = lv_source_mat target_count = lv_target_mat difference = lv_target_mat - lv_source_mat status = COND #( WHEN lv_target_mat = lv_source_mat THEN 'OK' ELSE 'MISMATCH' ) ) TO lt_recon. " GL Balance reconciliation " Compare total debit/credit per company code SELECT bukrs, SUM( CASE WHEN shkzg = 'S' THEN dmbtr ELSE 0 END ) AS total_debit, SUM( CASE WHEN shkzg = 'H' THEN dmbtr ELSE 0 END ) AS total_credit FROM bseg WHERE gjahr = @p_fiscal_year GROUP BY bukrs INTO TABLE @DATA(lt_target_balances). ``` ### Pattern 6: Cutover Plan Template ``` CUTOVER PLAN — Go-Live Weekend Friday Evening (T-36h): 18:00 Lock source system (stop business transactions) 18:30 Final delta extract from source 19:00 Run data quality checks on delta 20:00 Start delta migration load Saturday (T-24h): 06:00 Delta load complete — start validation 08:00 Run reconciliation reports 10:00 Fix data issues (correction runs) 12:00 Business validation (key users) 14:00 Go/No-Go decision point #1 15:00 Start integration testing 18:00 Integration testing complete Sunday (T-12h): 06:00 Final reconciliation 08:00 Go/No-Go decision point #2 (FINAL) 09:00 Open system for business users 09:00 Hypercare team on standby 12:00 First business transactions verified Rollback triggers: - Data reconciliation difference > 1% - Critical business process blocked - Integration interface failures > threshold ``` ## Error Catalog | Error | Message | Root Cause | Fix | |-------|---------|------------|-----| | LTMC: `Upload failed` | File format error | Wrong template version or encoding | Re-download template from current LTMC version | | LTMC: `Conversion error` | Value mapping failed | Source value not in mapping table | Add missing mapping; cleanse source data | | BAPI: `No authorization` | Authorization check failed | Migration user missing roles | Assign S_TCODE + object-specific auth | | `Duplicate key` | Record already exists | Re-run without clearing previous load | Delete previous test load or use update mode | | `Number range exhausted` | No numbers available | Number range too small for migration volume | Extend number range via SNRO | | `Referential integrity` | Dependent object missing | Load order wrong (e.g., PO before vendor) | Follow dependency sequence: master → transactional | | `Data truncation` | Field length exceeded | Source data longer than target field | Cleanse data or extend custom field length | | SUM: `Modification check` | Custom code conflict | ABAP modifications incompatible with S/4HANA | Fix with Custom Code Migration Worklist | | `Lock timeout` | Enqueue failed | Parallel migration jobs competing | Reduce parallelism or partition by org unit | | LTMC: `Simulate error` | Business rule violation | Data doesn't meet S/4HANA validation rules | Fix source data per validation message | ## Performance Tips 1. **Partition by org unit** — Migrate by company code/plant to parallelize and isolate failures 2. **Disable non-essential exits** — Temporarily deactivate BAdIs/user exits during bulk load 3. **Background processing** — Run LTMC in background mode for large volumes (>10K records) 4. **Number range buffering** — Enable buffering for migration-heavy number ranges 5. **Commit frequency** — Commit every 500-1000 records in custom programs; avoid single mega-commit 6. **Index management** — Drop secondary indexes before bulk load, rebuild after 7. **Load sequence** — Always: Config → Master Data → Open Items → Transactional Data 8. **Test with production volumes** — Never test with 100 records if production has 1M; timing differs non-linearly 9. **Delta strategy** — Plan for multiple delta loads; cutover window depends on delta volume ## Gotchas - **Business Partner migration**: S/4HANA merges Customer + Vendor into Business Partner — plan BP number assignment carefully - **Material number length**: S/4HANA supports 40-char material numbers but existing customizing may limit this - **New GL accounting**: If migrating from classic GL, open items need conversion to new GL structure - **LTMC template versions**: Templates change with S/4HANA releases — always download from target system - **Migration user**: Create dedicated migration user with broad auth; don't use dialog user to avoid session limits - **Tax code mapping**: Tax codes often differ between source and target — map explicitly, never assume - **Currency conversion**: If migrating across currencies, use ECB rates for the exact cutover date