ECC to S/4HANA: what actually changes
Every conversion inherits the same non-negotiables — and a set of choices nobody tells you about until the program is already scoped. We keep a vendor-neutral capability matrix, cited to SAP's own simplification catalog, and turn it into your roadmap: what you must replace, what you should review, and what becomes possible.
The delta, in numbers
| Module | Mandatory | Changed | Opportunities |
|---|---|---|---|
| CO | 1 | 0 | 1 |
| CO-ML | 1 | 1 | 0 |
| CO-PA | 0 | 1 | 1 |
| CROSS | 0 | 1 | 1 |
| FI-AA | 1 | 1 | 0 |
| FI-CONS | 0 | 0 | 1 |
| FI-GL | 1 | 0 | 3 |
| FI-RA | 1 | 0 | 1 |
| FSCM-CR | 1 | 1 | 0 |
| HCM | 0 | 1 | 1 |
| LO-ATP | 0 | 0 | 1 |
| MASTER-DATA | 1 | 1 | 1 |
| MM-IM | 1 | 0 | 1 |
| PP | 0 | 0 | 2 |
| SD | 2 | 0 | 2 |
| WM | 0 | 1 | 1 |
Coverage grows continuously — finance and receivables first, seeded from field programs and SAP's simplification catalog.
Separate customer and vendor master records (KNA1/LFA1-centric) maintained via classic transactions.
Fate: Business Partner is the mandatory leading object from the first S/4HANA release; CVI conversion is a hard conversion precondition. Successor: Business Partner + CVI.
Simplification Item: "S4TWL - Business Partner Approach" (SAP Note ID pending verification pass) · SAP Note 2265093 · effective from 1511 (in 1511 FPS02 list; note number printed there and in later lists)
Beneath the matrix: 1,252 documented changes
The capability matrix above is the executive view. Under it sits a line-by-line layer drawn from SAP's Simplification Lists and What's New guides — 680 of them cite an SAP Note — for the ECC → S/4HANA 2023 journey.
Output-relevant customizing must be rebuilt: output types → output parameter determination (BRFplus decision tables), forms → Adobe forms, print channel → print queue/bgRFC configuration; NAST-based custom print programs and requirement routines do not carry over. Technical prerequisites (ADS, bgRFC, BRFplus) must be set up as part of the conversion project.
CA-GTF-OC / SD · S4TWL - Output Management in SAP S/4HANA · SAP Note 2228611
The full list — filterable by module and change type, each row linked to its SAP Note, and tickable into your roadmap — is a customer feature.
Why the clock matters
ECC mainstream maintenance ends December 2027. Every S/4HANA release has its own clock too — five years for releases before 2023, seven from 2023 on — so the target you pick decides your next upgrade date.
| Release | Mainstream maintenance ends | Status today |
|---|---|---|
| S/4HANA 1511 | Dec 2020 | mainstream ended |
| S/4HANA 1610 | Dec 2021 | mainstream ended |
| S/4HANA 1709 | Dec 2022 | mainstream ended |
| S/4HANA 1809 | Dec 2023 | mainstream ended |
| S/4HANA 1909 | Dec 2024 | mainstream ended |
| S/4HANA 2020 | Dec 2025 | mainstream ended |
| S/4HANA 2021 | Dec 2026 | 4 months left |
| S/4HANA 2022 | Dec 2027 | 16 months left |
| S/4HANA 2023 | Dec 2030 | 4+ years |
| S/4HANA 2025 | Dec 2032 | 6+ years |
Dates per SAP's published release and maintenance strategy; 1709–1909 had paid extended maintenance to Dec 2025.
How the full advisor works
- Declare your footprint — what you actually run in ECC, capability by capability.
- Get the scoped delta — mandatory replacements, changed behaviour, opportunities: only yours.
- Receive the roadmap — Decide → Prepare → Convert → Adopt, starting with the transition-approach decision (brownfield, greenfield, or selective).
- See the outcome docs — the exact workshops, design decisions, configuration guides, tests and training your program must produce, mapped and counted.