Migration route

    SAP R/3SAP S/4HANA

    SAP R/3 to SAP S/4HANA Data Migration

    Migrate financials, master data, open items from SAP R/3 to SAP S/4HANA using a controlled process for extraction, mapping, transformation, validation, loading and reconciliation.

    Migration overview

    R/3 to S/4HANA is the longest jump inside the SAP family. Because a direct conversion from R/3 is generally not supported, the practical routes are a staged path through a supported release or a greenfield implementation with selective data transition.

    That makes the first decision architectural rather than technical, and it determines whether the programme is a conversion or a reimplementation carrying selected data.

    Typical data scope

    Scope is agreed in discovery. On this route it usually covers:

    Financials

    Domain in scope for a typical SAP R/3 to SAP S/4HANA programme.

    Master data

    Domain in scope for a typical SAP R/3 to SAP S/4HANA programme.

    Open items

    Domain in scope for a typical SAP R/3 to SAP S/4HANA programme.

    Migration architecture

    One controlled pipeline, run as repeatable cycles.

    SAP R/3DataMoveTransformation & validationSAP S/4HANADataVault reconciliationDataLens

    Extracting from SAP R/3

    What the source platform makes available, and the constraints that shape the extraction design.

    Non-Unicode codepagesMany R/3 installations were never converted to Unicode. Text sits under a legacy codepage, so extended characters need explicit conversion on extract. Skip it and names and addresses arrive corrupted — while every record count still reconciles, because the row is there and only its contents are wrong.
    Classic G/L rather than New G/LR/3 typically runs classic General Ledger: no document splitting, totals maintained separately from line items, segment reporting through special ledgers. The financial model being read is not the one a modern target expects.
    MANDT — client partitioningAs in ECC, application tables are client-dependent and an unconstrained extract blends clients.
    ADK archive filesData already archived out of R/3 lives in ADK archive files, not the database. If that history is in scope it must be read through the archive layer — a common late discovery on legacy estates.
    Custom Z-tables and modificationsA long-running R/3 estate accumulates custom tables and modified standard objects holding data the business depends on. Profiling finds them; a standard object list does not.
    Older extraction toolchainR/3 predates the modern integration surface. Extraction generally means ABAP extract programs or database-level reads rather than OData services.

    Source-to-target mapping

    A mapping workbook carries every field in scope from its SAP R/3 source through its transformation rule to the SAP S/4HANA target object and field. It is reviewed and approved with the business before the production migration, and applied identically in every cycle so a decision made once is not re-made under cutover pressure.

    Transformation challenges on this route

    The differences between SAP R/3 and SAP S/4HANA that create most of the work.

    Non-Unicode source

    Many R/3 systems were never converted. Codepage conversion is explicit, and the failure mode is invisible to record counts.

    Classic G/L to the Universal Journal

    The distance is significant: no document splitting and separately maintained totals on one side, a single merged line-item model on the other.

    Business Partner conversion

    Customers and vendors merge, exposing duplicates accumulated over the estate's whole life.

    Archived data in ADK files

    History archived out of R/3 is not reachable by SQL and needs the archive layer if it is in scope.

    Custom development volume

    Decades of modifications and Z-objects need inventorying against a target where several underlying structures no longer exist.

    How SAP S/4HANA accepts the data

    Load order is part of the design, not an implementation detail.

    1. 1Settle the conversion approach firstBrownfield system conversion, greenfield reimplementation, or selective data transition. This determines the entire data scope, so it is decided before any mapping work begins.
    2. 2Business Partner conversion is mandatoryCustomers and vendors must arrive as Business Partners through Customer/Vendor Integration. This is where most conversions find their master-data problems: duplicate parties, number-range collisions between customer and vendor ranges, and records never clean enough to merge.
    3. 3Load through the Migration CockpitPredefined migration objects and templates cover the standard object set, with staging tables for higher volumes. Custom objects need their own migration object built.
    4. 4Enterprise structure, then masters, then transactionsThe same dependency order as ECC, against a target model where several structures have changed shape.
    5. 5Respect the changed modelAggregate and index tables are gone, material number field length is extended, and inventory aggregates are derived rather than stored. Interfaces and custom code that assumed the old shapes need finding before cutover, not after.
    6. 6Reconcile against the Universal JournalFinancial reconciliation is built against ACDOCA rather than the ECC structures, so existing reconciliation logic is rebuilt rather than reused.

    Business Partner conversion is the item that most often surprises a programme. It is mandatory, it exposes every historic duplicate between the customer and vendor masters, and it cannot be deferred past cutover — so master data is cleansed before conversion, not after.

    Validation and reconciliation

    Validation before load

    Mandatory fields, referential integrity, format checks, business-rule validation and duplicate detection run on the prepared data, so problems surface as reportable exceptions rather than as failed loads in SAP S/4HANA.

    Reconciliation after load

    Source counts, transformed counts, rejected records and target counts, with control totals where the data supports them. Every discrepancy is categorised so the migration is approved on evidence rather than assertion.

    Migration cycles

    The pipeline is run end to end more than once before anything touches production. A typical structure is a first rehearsal that surfaces the bulk of mapping and data-quality corrections, a second that applies them and demonstrates production readiness, and the production cutover itself. How many cycles a programme needs depends on data quality and scope, which is established during discovery.

    1. 1Mock / PPR 1First full extract, transform, load, reconcile and exception analysis. Expect the largest correction list here.
    2. 2Mock / PPR 2Corrections applied, re-extract, re-run. Intended to closely replicate the production migration.
    3. 3Production cutoverFinal extract, data freeze, load, reconciliation, business validation and sign-off.

    Common risks on this route

    Path not decided

    Staged conversion and greenfield imply completely different scopes and timelines.

    Codepage handling assumed

    Validate character fidelity explicitly.

    Custom code inventory skipped

    Objects touching removed structures surface at go-live.

    Planning this migration?

    Tell us your source system, target platform, modules, data volumes and timeline. We can discuss the closest relevant migration experience and the recommended approach.