Convert, select or start fresh
All three paths are open: convert the whole system, carry over selected data and processes, or reimplement.
HistoryCustom codeConfiguration
Effort Largest change in software, smallest in process
Services / SAP Solutions / Move from ECC & On-Premise
Move from ECC & S/4HANA On-Premise
Choose your route to the cloud before the deadline chooses it for you.
Whether you're on SAP ECC or an older on-premise SAP S/4HANA release, there are four ways into SAP's cloud ERP. Each keeps something different and costs something different. We help you pick the right one, prepare your system for it, and run the move with rehearsed, measured downtime.
Where you're going. SAP Cloud ERP Private (through RISE with SAP) or SAP Cloud ERP (through GROW with SAP). This page covers the move itself.
SAPConversion Cockpit · PRD (ECC 6.0 EHP8)MK
Pre-checks
Simplification items
96% clear
Business partners
Customers and suppliers
18.4k
Database
After archiving
1.2TB
Preparation
Customer and supplier → business partnerDone
Asset accounting checksDone
Custom code fixes · 41278%
Archiving · FI documentsRunning
Downtime by rehearsal
Mock 151 h
Mock 237 h
Mock 329 h
Window42 h
The deadlines
Four options for an ECC system, and what each one costs you.
SAP's dates are fixed, and the window for the cheapest options is already narrowing. Before choosing a route, it helps to see every option on the table, including the ones we wouldn't recommend.
Option 1
Stay, pay extended maintenance
Keep ECC on SAP support until the end of 2030.
- Buys three years
- Two-point premium on your maintenance fee
- Only the last three enhancement packages qualify
- Pushes the project into the busiest years for SAP skills
Option 2
Switch to third-party support
Leave SAP support for an independent provider.
- Lower annual fee
- No SAP legal, tax or security updates
- Reinstatement fees if you return to SAP
- The move still has to happen eventually
Option 3
RISE transition option
Run ECC in SAP's private cloud with support until 2033, as a bridge.
- Three more years for very complex estates
- Only with a RISE contract, on SAP HANA by end of 2030
- Price uplift for commitments made after 2025
- Essential fixes only, no new features
Option 4 · Our advice for most
Plan the move now
Choose a route and start the preparation work this year.
- Your timing, not SAP's deadline
- Preparation done while ECC is stable
- Partner and SAP capacity still available
- Benefits start years earlier
Dates and conditions as published by SAP and reported by SAPinsider. The transition option also requires a minimum system size and SAP's top support plan. Confirm current terms for your contract.
Already on S/4HANA?
Your release has a date too.
Moving from ECC to S/4HANA on-premise wasn't the end of the road. Each on-premise release has its own maintenance end. Releases before 2023 got five years of mainstream maintenance. From 2023, SAP ships a release every two years, each with seven years of maintenance.
If your release is close to its end, the choice is another on-premise upgrade project, or moving to SAP Cloud ERP Private, where SAP runs the upgrades.
| Release | Mainstream maintenance to | Status |
|---|---|---|
| 1909 and earlier | Ended | Act now |
| 2020 | End of 2025 | Ended |
| 2021 | End of 2026 | Ending |
| 2022 | End of 2027 | Plan now |
| 2023 | End of 2030 | Supported |
| 2025 | End of 2032 | Current |
Based on SAP's published release and maintenance strategy. Check your exact release and feature pack in SAP's Product Availability Matrix.
Four routes
Where you are, where you're going, and what comes with you.
The starting system and the target decide which paths are open. SAP Cloud ERP (Public Edition) is always a fresh start. SAP Cloud ERP Private can take your existing system as it is.
ToSAP Cloud ERP PrivateToSAP Cloud ERP
SAP ECCECC 6.0, any enhancement pack
ECC → Cloud ERP Private
ECC → Cloud ERP
Fresh start, with data
A new implementation on SAP's standard processes. Master data and open items move across, and some can be pulled directly from ECC.
Master dataOpen itemsCustom codeFull history
Effort Biggest process change, cleanest result
S/4HANA on-premiseAny release you run today
S/4HANA → Cloud ERP Private
Move and upgrade
You're already on S/4HANA, so the system moves to SAP's private cloud and is brought up to a current release.
Everything
Effort The shortest route
S/4HANA → Cloud ERP
Fresh start, with data
A new implementation on the public edition, with master data and open items migrated. Worth it if you want SAP's standard and twice-yearly innovation.
Master dataOpen itemsCustom code
Effort Process change, simpler system to run
Effort is relative and depends heavily on how customised your system is and how clean your data is.
Selective data transition
The middle path, in four techniques.
Between converting everything and starting from scratch, there's a set of specialist techniques for choosing exactly what moves. They suit groups that want to restructure during the move, for example merging company codes, carving out a business, or going live country by country.
Shell conversion
Your system's configuration and custom code are converted without the business data. Selected data is then loaded into the clean shell.
Use when: your configuration is good but you want to leave old data and history behind.
Mix and match
A new S/4HANA system is installed, and only the configuration and code you choose are carried across. Everything else is rebuilt on standard.
Use when: some areas work well and others need a redesign.
Client transfer
A complete client, with its configuration, master and transaction data, moves into the new system. Several source systems can be merged.
Use when: you're consolidating several SAP systems into one.
Company code transfer
One company code at a time moves across with its data, while the rest of the business stays on ECC until its turn.
Use when: you want phased go-lives by country or business unit.
Selective data transition uses specialist tools from SAP and certified partners. It needs more planning than a conversion, but gives you control that neither of the other routes can.
Start now
Six things you can do this quarter, whatever route you pick.
The work that makes migrations late is mostly preparation, and most of it can start before you've signed anything. Every item below makes the move shorter, cheaper and less risky.
Run SAP's Readiness Check
A free SAP analysis of your system: which SAP changes affect you, how much custom code you use, and how large your data really is.
Why now: it turns opinions into numbers for your business case.
Convert customers and suppliers
S/4HANA replaces separate customer and supplier records with a single business partner. The conversion can be done, and tested, in ECC today.
Why now: it's often the longest data task, and it doesn't need the new system.
Archive old data
Archive closed years of documents you no longer need online. A smaller database means a shorter conversion weekend and lower running costs.
Why now: archiving has its own lead time and approvals.
Retire unused custom code
Usage statistics show which programs nobody has run in a year. Deleting them now means nothing to adapt, test or migrate later.
Why now: every object removed is one less to fix.
Clean up finance
S/4HANA brings everything into one financial journal. Asset accounting, ledgers and reconciliation issues need to be resolved first.
Why now: finance checks are the most common conversion blocker.
Cleanse master data
Duplicate customers, blocked suppliers, unused materials and missing tax numbers. Fix them once at the source.
Why now: it pays off on every route, including a fresh start.
What changes inside
The changes you'll meet, and how much each one matters.
S/4HANA isn't ECC on a faster database. SAP simplified the data model and replaced several older functions. SAP's Readiness Check lists the ones relevant to your system. These are the ones almost every ECC customer meets.
| Area | In ECC | In S/4HANA | Impact |
|---|---|---|---|
| Customers and suppliers | Separate customer and vendor records | One business partner for both, converted before the move | High |
| Finance | Separate GL, CO, asset and material tables reconciled at month-end | One universal journal for all postings, with new asset accounting | High |
| Inventory valuation | Material ledger optional | Material ledger always on, with actual costing optional | Medium |
| Credit management | Credit checks in sales | SAP Credit Management, with credit segments and rules | Medium |
| Rebates | Rebate agreements in sales | Settlement management with condition contracts | Medium |
| Warehouse | Classic warehouse management | Extended Warehouse Management is the strategic option | Medium |
| Material numbers | Up to 18 characters | Up to 40 characters, which matters for interfaces and custom code | Low |
| User interface | SAP GUI transactions | Role-based Fiori apps, with SAP GUI still available in Private Edition | Medium |
| Output | Classic output conditions and forms | New output management framework alongside the classic one | Low |
Impact is typical, not universal. A business that uses classic warehouse management heavily, for example, will rate it high.
Inside a system conversion
Eight steps, rehearsed until they're routine.
For conversions to SAP Cloud ERP Private, the sequence is well established. What makes it safe is repetition. We run the whole sequence on copies of your production system until timings are known and every issue has a fix.
1
Assess
Readiness Check, simplification items, custom code analysis and sizing.
2
Prepare
Business partner conversion, finance checks, archiving and code clean-up in ECC.
3
Convert
Database and software converted to SAP S/4HANA in one technical run, using SAP's own conversion tools.
4
Migrate finance
Historical finance data rebuilt into the new single journal, then reconciled to the old totals.
5
Adapt code
Remaining custom code fixed for S/4HANA's data model, or replaced by standard.
6
Roles and Fiori
Users moved from old transactions to role-based Fiori apps, with roles rebuilt to match.
7
Test
Regression, integration and user acceptance tests on the converted system.
8
Cut over
The final run on production over a planned weekend, with a fallback plan ready.
Steps 3 to 7 are repeated in at least two or three mock conversions before production.
Downtime
Measured in rehearsals, not promised in a proposal.
The question every board asks is how long the business will be offline. The honest answer comes from mock conversions on a copy of your production data. Each rehearsal is faster than the last, as we archive more, tune the run and parallelise the steps.
The method matters too. SAP's conversion tooling offers several ways to move work out of the downtime window. We pick one based on your database size and how long the business can stop.
Business downtime by rehearsal
Example. The dashed line is a 42-hour weekend window.
Mock 151 h
Mock 237 h
Mock 329 h
Production28 h
Illustrative. Real figures depend on database size, hardware, archiving and the conversion method.
Standard conversion
Database migration and software conversion in one run during the downtime window.
Most systemsDowntime-optimised
Large tables and much of the finance conversion run while the business keeps working, leaving a smaller final step.
Large systemsNear-zero downtime
A specialist service that replicates changes continuously, so the switch-over takes hours.
24/7 operationsCustom code
Most of it shouldn't make the trip.
A typical ECC system carries thousands of custom objects built over fifteen years or more. SAP's own analysis tools show which ones are actually used, and which ones S/4HANA's changes will break. Usually, the majority can simply be retired.
Usage dataMonths of real usage statistics collected from production, so nothing is retired on a guess.
Custom code checksSAP's automated checks flag every object affected by the simplifications above.
Quick fixesMany findings are fixed automatically in SAP's development tools.
Clean core reviewCode that stays is rebuilt on released interfaces, or moved to SAP BTP, so it survives future upgrades.
Custom objects found4,200
Unused, retired · 56%2,350
Replaced by standard · 15%650
Adapted · 23%980
Rebuilt clean core · 5%220
Illustrative example from a mid-sized ECC system.
Beyond the ERP
The systems around ECC have deadlines too.
ERP rarely moves alone. The systems around it are often on the same maintenance clock, and they're easy to forget until late in the plan. We map your whole SAP landscape in the assessment.
From SAP PI/PO
Integration Suite
Interfaces move from Process Integration to SAP Integration Suite. SAP provides migration tooling for many standard patterns.
Mainstream maintenance ends 2027From SAP CRM, SRM, SCM
Into S/4HANA or the cloud
Many functions are now in S/4HANA itself. Others move to SAP's cloud products. These systems aren't covered by the ECC transition option.
Same 2027 and 2030 dates as ECCFrom SAP BW
Analytics and data
Reporting moves to embedded S/4HANA analytics, SAP BW/4HANA or SAP's Business Data Cloud, depending on what you report on.
Plan alongside ERPFrom GRC and roles
Access and security
Transaction-based roles are rebuilt around Fiori apps, and access controls are revalidated for the new roles.
Part of every conversionFrom third-party interfaces
Partner systems
Banks, e-commerce, logistics and payroll interfaces are checked for data model changes, such as business partners and longer material numbers.
Test earlyFrom non-HANA databases
SAP HANA
Systems on Oracle, SQL Server or DB2 move to SAP HANA as part of the conversion, which also affects database licensing.
Required for S/4HANAAfter the move
A technical move is the start, not the finish.
A conversion keeps your processes the same, so the business benefits come from what you switch on afterwards. We plan these in from the start, so the move pays for itself.
Finance
One journal, faster close
All finance and controlling in one table: real-time margin reporting, no reconciliation between ledgers, and a shorter month-end.
People
Fiori for every role
Role-based apps and a personal home page replace transaction codes. Training focuses on what changes for each role.
Insight
Live analytics
Reports that run directly on live transactions, plus alerts for late deliveries, credit blocks and unbilled orders.
AI
Joule and AI agents
SAP's AI works on S/4HANA's data model, not on ECC. The move is what opens the door.
Operations
Less to run
SAP runs the infrastructure, database and technical operations, so your team can move from keeping the lights on to improving processes.
Clean core
Easier upgrades
With custom code cleaned up and new extensions built the upgrade-safe way, future releases become routine.
© 2026 Mawkish Technologies. This guide, its diagrams and illustrations are protected by copyright. You’re welcome to learn from it and to quote it with credit and a link. Reproducing it, by hand or through AI, and publishing it as your own is not allowed. Read our copyright notice
Questions we hear
Straight answers.
When exactly does SAP stop supporting ECC?
Mainstream maintenance ends at the end of 2027. Extended maintenance runs from 2028 to the end of 2030 at a two-point premium, and only for the last three enhancement packages. After that, the only SAP-supported option is the RISE transition option to 2033, which needs a RISE contract and an SAP HANA system moved into SAP's private cloud by the end of 2030.
Should we wait for the 2033 option?
Only if your landscape is genuinely too complex to move by 2030. It provides essential fixes but no new features, the price rises for later commitments, and the project still has to happen. For most mid-sized companies, it costs more than it saves.
We're already on S/4HANA on-premise. Do we need to move?
Check your release. Releases before 2023 had five years of mainstream maintenance, and several have ended or end soon. From 2023, each release gets seven years. Moving an existing S/4HANA system to SAP Cloud ERP Private is the shortest route on this page and stops the cycle of upgrade projects.
Our ECC runs on Oracle or SQL Server. Is that a problem?
No, but it adds a database migration to SAP HANA. SAP's conversion tools handle the database migration and the software conversion in one run. The database size after archiving is what drives the downtime.
What happens to our history if we choose a fresh start?
Open items, balances and master data move across. Older history usually stays in a read-only copy of the old system or an archive for audit and reference. Selective data transition can bring a defined number of years of history into the new system if you need it.
How long does a conversion take?
Typically 12 to 24 months from assessment to go-live, depending on system size, custom code, data quality and integrations. Preparation work done in advance shortens it.
Can we change processes during a conversion?
Keep it limited. The safest approach is to convert first, then improve processes in planned waves after go-live. If you need to restructure during the move, for example by merging company codes, selective data transition is the better route.
Start here
Know your route, your effort and your downtime.
Our migration assessment runs SAP's Readiness Check on your system, analyses your custom code and data, and gives you a recommended route with a timeline and budget range.
- Recommended route, with reasons
- Custom code findings and clean-up plan
- Preparation work you can start now
- Downtime estimate and approach
- Timeline, team and budget range
SAP, SAP ECC, SAP S/4HANA and RISE with SAP are trademarks of SAP SE. Screens shown are illustrations.
Our Junleigh Rule is the name we give to how we handle Move from SAP ECC & On-Premise to Cloud ERP: one accountable partner, from the first meeting to long after go-live.