S/4HANA Brownfield vs Greenfield Statistics (2026)

Brownfield (system conversion), greenfield (new implementation) and the hybrid middle path are the three routes most ECC programs weigh before a sign-off. This page collects the published numbers behind that choice: how far customers have moved, which approach they picked, how long projects ran, and where they failed. Each figure carries its year, population and source.

Most of the approach-mix data comes from surveys with different samples and dates, so the splits do not line up neatly. We flag those gaps in the notes rather than averaging them.

Key takeaways

Adoption: where ECC customers stand

Adoption figures are the most-quoted numbers in this space, and the most often misread. Gartner's series tracks licenses, not completed go-lives.

• Gartner estimated that about 39% of roughly 35,000 worldwide ECC customers had bought or subscribed to S/4HANA licenses by the end of 2024, as reported by The Register in March 2025.
• The same Gartner series put the figure at 37% in Q2 2024 and 34% a year earlier, per The Register.
• At the prevailing pace, Gartner projected about 17,000 ECC holdouts in 2027, close to half the installed base, according to CIO's reporting of Gartner.
• Gartner's earlier estimate, from early 2025, was that more than 60% of SAP customers remained on ECC 6 on-premises with no decision yet to move, as Gartner's paper was reported by The Register in February 2025.

Source: The Register, March 2025 (Gartner); CIO, 2025 (Horváth study)

Source: The Register, March 2025 (Gartner licensing series)

• A valantic and techconsult study of 201 SAP decision-makers in 2025 found ongoing S/4HANA migration projects rose from 21% in 2024 to 40%, and 27% had completed a migration, per valantic's SAP Study 2025.
• A SAPinsider 2026 survey, as summarized by Peterson Technology Partners in October 2026, reported 34% had completed their transition, and 36% were at an early stage (just starting, evaluating or building the business case).

Source: valantic SAP Study 2025 (201 respondents, with techconsult)

Approach mix: brownfield, greenfield and bluefield

The three approach labels are not defined the same way across sources. Some surveys treat hybrid as a separate option and some fold it into greenfield. The splits below therefore show direction, not a single market answer.

• ISG's 2026 research, as reported by SoftwareSeni, placed bluefield or selective data transition first, followed by brownfield and greenfield, per SoftwareSeni's 2026 analysis. We could not reach the ISG report itself.
• The earlier LeanIX and PwC study from 2018 (historical) found only 14% of respondents intended a full greenfield route, with 44% choosing brownfield and 42% a combined approach, per LeanIX's 2018 press release.
• A split reported by Orpington Technologies from ASUG respondents shows 26% greenfield, 29% bluefield and 44% brownfield. The source does not state a survey year, so treat this one as undated.

Source: SoftwareSeni, 2026 (citing ISG 2026 research)

Source: LeanIX / PwC study, 2018 (historical)

Source: Orpington Technologies, reporting ASUG respondents (undated)

Conflict to note: Greenfield shows 14% in the 2018 LeanIX/PwC study, 18% in ISG's 2026 research and 26% in the undated ASUG split. Bluefield is absent from the 2018 study, which predates the term's wide use. Sample frame, year and definitions all differ, so we do not treat these as a trend line.

Timelines and schedule performance

• Horváth's Q1 2025 survey covered 200 SAP user companies with annual revenue of at least €200 million, and found projects ran on average 30% longer than originally planned, per CIO's coverage of the study.
• Of the companies that had completed the move, only 8% had done so on schedule, in the same Horváth survey, per CIO.
• The same survey counted 37 of 200 companies as complete, with 57% still mid-transformation, per CIO.
• ISG's 2026 research of 200 senior SAP decision-makers found 60% of migration projects ran over budget or over time, regardless of approach, per SoftwareSeni.
• Gartner has seen clients plan three- to seven-year migration projects, per CIO's reporting of Gartner.

Conflict to note on duration: Panorama Consulting says a full S/4HANA migration typically runs 18 to 36 months, depending on data volume, customization and whether the firm rebuilds or converts. Incorta puts most migrations at 12 to 24 months, and IBsolution gives a similar range for typical implementations. Both are vendor or consultancy blogs with no stated sample. The gap probably reflects scope: the longer range covers large, heavily customized landscapes, while the shorter one covers narrower conversions.

Failure drivers and risk

The Horváth survey gives the most detailed failure breakdown we could source. Respondents could name more than one cause.

• Lack of IT integration perspective in the overall project was cited by 28% of respondents, per the Horváth study as reported by CIO.
• Insufficiently defined processes came next at 24%, and missing knowledge of third-party systems and interfaces at 23%, in the same survey.
• Lack of resources and a poorly placed project manager were each cited by 20%.

Source: CIO, 2025 (Horváth study, 200 companies, Q1 2025)

Two case reports from 2026 show what the approach choice looks like in practice. Peterson Technology Partners reports that Nestlé cut its planned conversion outage to 19.5 hours, down from an initial estimate of 48 hours, after months of work to shrink the window, per PTP's October 2026 report. These are single-company results, not sample statistics. SAP's Q2 2026 call also cited Dexco eliminating roughly 97% of legacy customizations through SAP's integrated toolchain, as reported by Investing.com. That is a vendor-published customer claim, so we label it as vendor data.

Cost, cloud and commercial pressure

• In a Rimini Street survey of 455 organizations, nine in 10 SAP customers said they were concerned about rising and unpredictable subscription costs over time, per CIO's report on that survey. Rimini Street sells third-party support, so weigh the finding accordingly.
• In the same survey, nearly half did not expect to be running S/4HANA in the cloud five years out, and nearly a quarter planned to stay on on-premises ECC, per CIO.
• Horváth found hosting preferences split sharply: 48% chose private cloud and 19% on-premises, with just under 30% choosing public cloud, per CIO.
• In valantic's 2025 study, 58% preferred the managed S/4HANA private cloud as their deployment model, per valantic.

Source: CIO, 2025 (Horváth study, 200 companies)

Maintenance cost is the other lever. Extended maintenance from 2028 to 2030 adds two percentage points to the maintenance basis, and Crowe estimates the total increase at 9% to 12% once SAP's annual index increases are included, per Crowe. Rimini Street describes the same premium as roughly 9%, without the index effect. The two framings differ, so check which one applies to your contract.

Testing and quality

Sourced numbers on testing effort, defect rates and test automation coverage for ECC-to-S/4HANA programs were not available in the sources we could reach, so this section stays short. Quality-adjacent figures we could source are below.

• SAPinsider's State of the Market benchmark (undated) reported that 85% of respondents who had completed an S/4HANA project said it met or exceeded their expectations, per the SAPinsider report. Treat this as historical and self-selected, since it counts only finished projects.
• A CIO article citing a 2025 SAPinsider migration report named managing customizations, third-party applications and data hygiene as high-ranking technical challenges, per CIO. That report's findings do not include a usable percentage in the coverage we reviewed.

People, partners and skills

• An IDC figure in H&L's October 2024 SAP overview estimated that about 77% of SAP customers would rely on a partner for their S/4HANA migration, per H&L citing IDC. This figure is historical and was not restated in 2026 sources we found.
• An IDC survey of 300 SAP customers, undated in the coverage we reviewed, found 54% planned to implement S/4HANA within three years, and 43% planned to consolidate several ERP instances into one, per IgniteSAP's report on IDC research.

AI and outlook

• SAP reported a current cloud backlog of €22.9 billion at the end of Q2 2026, up 27% (26% at constant currencies), per SAP's Quarterly Statement Q2 2026. The backlog grows with cloud contracts, not with migration counts, so read it as a direction signal only.
• SAP's roadmap for ECC places mainstream maintenance for enhancement packages 6 to 8 at December 31, 2027, with an extended option through 2030, per Incorta's 2027 guide. Enhancement packages 0 to 5 lost mainstream maintenance at the end of 2025, per Rimini Street.
• For RISE customers, SAP's transition option covers the period from 2031 through 2033, as SAP's spokesperson described in January 2025.
• Compatibility Packs, which let customers keep some classic ECC functions on S/4HANA on-premises during the transition, expired in May 2026, per Essenn Associates.

Source: The Register, March 2025 (Gartner); CIO, 2025 (Horváth)

What this means for your sign-off

• Plan for overrun by default. If the Horváth pattern holds, a 30% time overrun is the planning baseline, not a risk case. Build your regression and cutover windows against a longer timeline, and show the sponsor where the buffer sits.
• Pick the approach on scope, then test the scope. The approach choice moves the test population. A brownfield conversion carries custom code forward for regression, while selective transitions and greenfield rebuilds need new scripts for redesigned processes. Scope these in the phase-by-phase migration test plan.
• Treat interfaces as a test workstream. Undocumented third-party systems and interfaces were a leading failure cause in the Horváth survey, so an interface inventory should be an exit criterion, not a backlog item.
• Use the Gartner number with care. Licensed is not the same as migrated. When a steering committee asks how the market is doing, report the licensed and migrating figure separately from completed go-lives. Our S/4HANA migration by the numbers page sets out how to read the figures.
• Build the CoE before the cutover crunch. Where resourcing is the constraint, the SAP Testing CoE operating model shows how to fund and staff shared test capacity.
• Keep the regression engine running after go-live. Cloud contracts bring a fixed upgrade rhythm. If you choose a managed private edition, the S/4HANA upgrade cadence and regression strategy applies from day one.

Frequently asked questions

What share of SAP ECC customers had moved to S/4HANA by the end of 2024?

Gartner estimated about 39% of roughly 35,000 ECC customers had licensed or begun moving to S/4HANA by the end of 2024, per The Register. That figure counts licenses, so it is not a completed-migration count.

Which approach is most common in 2026?

ISG's 2026 research, as summarized by SoftwareSeni, puts bluefield or selective data transition at about 48%, brownfield at 34% and greenfield at 18%, per SoftwareSeni.

How much do S/4HANA projects overrun on time?

Horváth's Q1 2025 survey of 200 SAP user companies found projects ran on average 30% longer than planned, per CIO.

How long does a full S/4HANA migration take?

Panorama Consulting says a full migration typically takes 18 to 36 months, while Incorta puts most migrations at 12 to 24 months. The two sources do not state their samples, so use the range that matches your scope.

What is the most common cause of migration failure?

In the Horváth survey, missing IT integration perspective was the most cited cause at 28%, ahead of insufficiently defined processes at 24%, per CIO.

How much extra does extended ECC maintenance cost?

Extended maintenance adds two percentage points to the maintenance basis, and Crowe estimates a total increase of 9% to 12% once annual index increases are included, per Crowe.

Sources

1. Legacy SAP ERP customers still foot-dragging move to S/4HANA, The Register, March 20, 2025
2. Why SAP may be mulling 2030 end of maintenance for legacy ERP, The Register, February 12, 2025
3. Nearly half of SAP ECC customers may stick with legacy ERP beyond 2027, CIO, 2025 (Gartner)
4. SAP customers struggle with S/4HANA migration, CIO, 2025 (Horváth study, Q1 2025 fieldwork)
5. SAP customers not sold on S/4HANA ROI, CIO, 2025 (Rimini Street survey of 455 organizations)
6. ERP Migration Countdown: The Changing Economics of Greenfield vs Brownfield, Peterson Technology Partners, October 13, 2026
7. valantic SAP Study 2025, valantic with techconsult, 2025
8. SAP Quarterly Statement Q2 2026, SAP SE, July 2026
9. SAP Q2 2026 slides: cloud backlog surges 27% amid margin pressure, Investing.com, 2026
10. Brownfield Greenfield or Bluefield: Choosing the Right SAP Migration Path With the Data, SoftwareSeni, 2026 (citing ISG 2026)
11. Survey Reveals Current State of SAP S/4HANA Migrations, LeanIX, September 4, 2018 (LeanIX/PwC study, historical)
12. SAP ECC to S/4HANA Migration Strategies: Brownfield, Greenfield, and Selective (Bluefield) Transition, Orpington Technologies, undated
13. 18 Months to the SAP ECC Cliff and Half of Customers Still Haven't Moved, Panorama Consulting Group, July 24, 2026
14. SAP ECC End of Support 2027: What It Means and What to Do Next, Incorta, undated
15. End of maintenance for SAP ECC in 2027: What companies can still do now, IBsolution, undated
16. SAP ECC Support Ends in 2027: What Leaders Should Do, Crowe, undated
17. No Extension to SAP ECC 6 and Business Suite 7 Mainstream Maintenance End Dates in 2025 and 2027, Rimini Street, undated
18. The SAP 2027 Deadline: ECC End of Maintenance Explained, Essenn Associates, 2026
19. The road to S/4HANA: How CIOs are managing SAP ECC's end of support, CIO, 2025 (citing SAPinsider)
20. SAP Industry Overview and Insights, October 2024, H&L, 2024 (citing IDC, historical)
21. Survey Finds More Than Half of SAP Users Plan on Moving to S/4 HANA, IgniteSAP, undated (citing IDC, historical)
22. SAPinsider Benchmark Report: SAP S/4HANA State of the Market, SAPinsider, undated (historical)

Last updated: October 26, 2026. Statistics are refreshed as new research is published.