Published November 3, 2026
The deadline
SAP provides mainstream maintenance for SAP Business Suite 7 core applications until the end of 2027. For SAP ERP 6.0, the commitment covers the latest three enhancement packages, EHP 6, 7 and 8.
Optional extended maintenance runs from the start of 2028 to the end of 2030. It costs a premium of two percentage points on the maintenance basis. Customers who do not take it, or whose extended maintenance has ended, move to customer-specific maintenance.
Systems with no enhancement package or with EHP 1 to 5 are outside the 2027 commitment. SAP told those customers they could extend mainstream maintenance to 2027 by upgrading to EHP 6 to 8.
SAP has committed that at least one release of SAP S/4HANA will be in maintenance until 2040. A new S/4HANA release ships every two years.
The decision: convert, rebuild or carve out
The first decision is how much of the current system to keep. A conversion keeps it all. It also carries every custom program, every workaround and every year of data into the new system.
Rebuilding gives a clean design and costs a full implementation: process design, configuration, data migration and training for everyone who uses the system.
The answer depends on whether the business wants its current processes. If most processes are sound, convert. If most need redesign, rebuild. If the answer differs by company code, region or business unit, consider a selective transition.
The three approaches
| Approach | What SAP describes | Main tools |
|---|---|---|
| System conversion (brownfield) | Changes an existing SAP ERP system into an S/4HANA system. Configuration, custom code and data are converted, not rebuilt. | Maintenance Planner, Simplification Item Check, Custom Code Migration tool, Software Update Manager (SUM) |
| New implementation (greenfield) | A new installation of S/4HANA, configured from SAP Best Practices or the Implementation Guide, with master and business data migrated in. | SAP S/4HANA migration cockpit, SAP Activate |
| Selective data transition | Move selected business data, and optionally selected history, while redesigning processes. Variants include a shell conversion and a mix-and-match build. | SAP Landscape Transformation plus expert functions that SAP does not make generally available |
In a shell conversion, a copy of production without master or transaction data is converted, then selected data is moved in. SAP says this suits cases where most original processes are reused. Mix and match starts from a new installation and brings over chosen configuration and code. SAP says this suits cases where most of the solution is redesigned.
For a selective transition, SAP strongly advises engaging SAP's own services or a specialized partner.
The order of the work
- Find your starting point. Record the ERP release, enhancement package, database, Unicode and dual-stack status, and installed add-ons.
- Run SAP Readiness Check. It analyzes the ERP 6.0 system for relevant simplification items, custom code, add-on compatibility, integration and sizing. SAP includes it in standard support.
- Read every simplification item that applies. Each one describes a business process that was removed, changed or replaced, and the steps it needs before and after conversion.
- Choose the approach per system, using the Readiness Check results, the custom code count and the business view of current processes.
- Fix the prerequisites. A conversion requires a Unicode system and an ABAP-only system. A non-Unicode system needs a Unicode conversion first. A dual-stack system needs a split first.
- Convert customers and suppliers to business partners. SAP's conversion documentation requires every customer and supplier record to become a business partner before the move, including records flagged for deletion that are not archived.
- Reduce data volume. Archive what the business no longer needs online. Less data shortens the conversion.
- Remediate custom code. Run the Custom Code Migration checks and retire code nobody uses.
- Rehearse. Convert a copy of development first, then repeat the full conversion on production-sized copies until the runtime fits the downtime window.
- Cut over, then finish. SUM migrates the database to SAP HANA if needed, updates the software and converts the data. Follow-on steps, custom code adaptation and Fiori setup come after.
Plan these early
- Business partner conversion. Inconsistent customer and supplier records, broken links between them and gaps in customizing such as tax numbers all have to be fixed first. Start it as its own project well before the conversion.
- Custom code. SAP states that its custom code checks do not yet find every instance where code does not comply with S/4HANA. Code still has to be tested in S/4HANA.
- Finance. Finance has its own conversion steps and SAP Note 2332030. Reconciliation before and after conversion needs finance staff, not only consultants.
- Downtime. Production conversion runtime grows with data volume. Measure it on full-size copies. SUM offers a downtime-optimized conversion, and on S/4HANA Cloud Private Edition SAP requires an expert trained on course ADM329 to run it.
- Add-ons and business functions. The Maintenance Planner checks add-ons, active business functions and industry solutions. If any of them has no valid conversion path, it prevents the conversion.
Functions that are replaced, not converted
The Conversion Guide lists application changes that need preparation. Several mean a new product or a new process, not a technical step:
- Foreign trade is replaced by SAP Global Trade Services.
- Revenue recognition in sales is replaced by SAP Revenue Accounting and Reporting.
- SD rebate processing is replaced by Settlement Management.
- SAP Credit Management and cash management have their own conversion tasks. SD pricing and inventory management have new data models.
- Material numbers are extended. SAP provides a check program for the extension.
Each of these needs an owner in the business and a test case. Find them in the Readiness Check results before the budget is set.
Maintenance terms and the cost of time
A conversion that will not finish by the end of 2027 needs a maintenance decision. Extended maintenance to the end of 2030 adds two percentage points to the maintenance basis. Without it, the system moves to customer-specific maintenance, which SAP described in 2020 as problem solving for known issues at unchanged fees.
SAP also sells a transition option for SAP ERP, private edition. It is a cloud subscription centered on ECC for customers who need more time. SAP announced it for use from 2031 to the end of 2033. It is available only to customers who have already moved to SAP ERP, private edition, and systems must run it on SAP HANA before December 31, 2030. SAP lists further prerequisites, including a minimum system size of 2 TB and the max success plan. An SAP update dated October 13, 2026 says these subscriptions may run until December 31, 2035. SAP says the option is not a maintenance prolongation of SAP ERP and changes nothing for on-premises SAP ERP systems after 2030.
The SAP S/4HANA migration cockpit is included in the S/4HANA license.
Skills and operations
A conversion needs Basis staff for SUM and HANA, ABAP developers for code remediation, and functional leads for each simplification item. A new implementation needs process owners from the business for design and testing.
The project runs alongside normal support. Changes to the ECC system during the project have to be applied to the conversion landscape too. SAP recommends a second development system, copied from the first, to run and test the conversion while transports collect the changes.
After go-live, plan for upgrades. Each S/4HANA release needs custom code checks, regression testing and end user training.
Settle these first
- Which release and enhancement package is each ERP system on, and is it Unicode?
- Which processes does the business want to keep, and which does it want to redesign?
- How much custom code is used in production, and how much can be retired?
- Which add-ons and interfaces depend on functions that S/4HANA replaces?
- Will the move finish before the end of 2027, and if not, which maintenance option covers the gap?
Questions
- When does SAP ECC maintenance end?
- Mainstream maintenance for SAP ERP 6.0 EHP 6, 7 and 8 ends at the end of 2027. Optional extended maintenance runs to the end of 2030 at a premium of two percentage points. After that, customers move to customer-specific maintenance.
- Can we convert directly from any ECC enhancement package?
- For S/4HANA 2025, a single-step conversion is supported from SAP ERP 6.0 EHP 0 to 8, with restrictions for some support package levels. The system must be Unicode and ABAP-only.
- Is brownfield or greenfield better?
- Neither in general. A system conversion keeps processes, code and history. A new implementation starts clean and needs full process design and data migration. A selective transition mixes the two.
- Does SAP Readiness Check replace the Simplification Item Check?
- No. SAP says both are required. SAP Readiness Check is a planning tool run early. The Simplification Item Check is mandatory, and the Software Update Manager runs it a final time before downtime.
- Do we have to move to SAP HANA first?
- No. S/4HANA runs only on SAP HANA, but the Software Update Manager migrates the database during the conversion if the system is not yet on HANA.