For Japanese companies running SAP ERP, one date dominates IT planning: the end of 2027. That is when mainstream maintenance ends for SAP ERP 6.0 (often called SAP ECC) on the most widely used enhancement packages. In Japan, the challenge is widely known as the “SAP 2027 problem” (SAP 2027年問題).
For SMEs and mid-sized companies, the move to SAP S/4HANA can look like an expensive, risky project designed for large enterprises. It does not have to be. Approached correctly, SAP S/4HANA migration in Japan can be a cost-effective DX project that simplifies processes, improves data quality and creates a foundation for analytics and AI. This article explains the deadlines, the options and how to keep the project under control.
Understanding the deadlines
- End of 2027: Mainstream maintenance ends for SAP ERP 6.0 with enhancement packages 6 to 8, which covers most existing SAP customers.
- 2028 to 2030: Companies can purchase optional extended maintenance until the end of 2030, for an additional two percentage points on top of the standard maintenance fee. It is intended as a transitional measure.
- 2031 to 2033: Announced in February 2025 and detailed in August 2025, the “SAP ERP, private edition, transition option” is a time-bound RISE with SAP subscription for large, complex customers. Systems must move to SAP ERP, private edition on SAP HANA before 31 December 2030; it can be purchased from 2028 for use from 2031 to 2033, and it requires a minimum 2 TB system size and the paid “max success plan.” SAP stresses that it is not an extension of maintenance (as of September 2026).
For most SMEs, the realistic planning horizon is 2027 to 2030. Waiting until the last moment increases cost, because experienced consultants become scarce and expensive as deadlines approach.
Why S/4HANA is more than a technical upgrade
S/4HANA is not simply a new version of ECC. It runs only on SAP’s in-memory HANA database, uses a simplified data model, and includes redesigned processes and user interfaces (SAP Fiori). Key changes include:
- Simplified finance, with a single source of truth for financial and management accounting (the Universal Journal).
- Real-time reporting and analytics directly on transactional data.
- Mandatory business partner model for customers and vendors.
- Modern, role-based user experience accessible via browser and mobile devices.
These changes are what make S/4HANA valuable as DX ERP solutions, but they also mean migration requires business and data preparation, not only technical work.
Your migration options
Greenfield (new implementation)
Start fresh with a new S/4HANA system, redesigning processes around SAP standard functions. Historical data is migrated selectively.
Best for: companies with heavily customised or outdated processes that want a clean start.
Brownfield (system conversion)
Convert the existing ECC system to S/4HANA, keeping configuration, custom code and history.
Best for: companies whose processes still work well and who want to minimise business disruption.
Selective data transition (hybrid)
Combine elements of both: build a new system but move selected historical data, organisational units or configuration.
Best for: companies with complex landscapes, mergers, or a need to consolidate several systems.
Deployment choices
- On-premises or private cloud: maximum control and flexibility; RISE with SAP bundles SAP Cloud ERP Private (formerly SAP S/4HANA Cloud Private Edition) with infrastructure and services in a subscription.
- Public cloud: SAP Cloud ERP (formerly SAP S/4HANA Cloud Public Edition), offered through GROW with SAP, targets fast, standardised implementations and is often attractive for mid-sized companies willing to adopt standard processes.
Alternatives to consider
For smaller companies, it is worth asking whether full S/4HANA is the right fit at all. SAP’s portfolio for smaller businesses, and other ERP products, may meet requirements at lower cost. A short, independent assessment before committing avoids overspending.
How SMEs can keep costs under control
1. Clean up before you migrate. Archive old data, remove unused custom code and fix master data quality. Every unnecessary object migrated adds cost.
2. Adopt a “clean core” and fit-to-standard mindset. Use standard SAP processes wherever possible and build extensions outside the core. This reduces migration effort now and upgrade costs later.
3. Analyse custom code early. SAP provides tools to identify which custom programmes are incompatible with S/4HANA. Many SMEs find that a large share of their custom code is no longer used.
4. Rationalise add-ons and satellite tools. Many SAP environments are surrounded by Excel and VBA tools, interfaces and small applications. Decide which to replace with standard functions, which to rebuild and which to retire.
5. Phase the project. Prioritise core finance and logistics, then add advanced functions such as analytics, planning or AI after go-live.
6. Use a blended delivery team. Combining Japan-based consultants for business design and user engagement with offshore teams for development, testing and data migration can significantly reduce costs without compromising quality.
7. Check support schemes. Depending on scope, some national or local support for digital investment may apply. Confirm eligibility with official programme guidelines.
A practical migration roadmap
- Assessment (1 to 3 months): Review your current system, custom code, data volume, interfaces and business requirements. Choose the migration approach and deployment model, and build the business case.
- Preparation: Clean up data, archive, remove unused code, and prepare master data, including the business partner conversion.
- Design and build: Configure the new system, adapt or rebuild necessary extensions, and redesign interfaces.
- Testing: Run multiple test cycles, including full data migration rehearsals and user acceptance testing with business teams.
- Cutover and go-live: Plan cutover carefully around period-end closing and busy seasons, with clear fallback plans.
- Stabilisation and improvement: Support users intensively after go-live, then introduce further improvements in planned releases.
Common pitfalls
- Treating it as an IT-only project. Finance, sales, production and procurement must own their processes.
- Underestimating data work. Poor master data is one of the most common causes of delays.
- Recreating old customisations. Copying past workarounds into S/4HANA wastes the opportunity to simplify.
- Late user training. Fiori and new processes require change management, especially for experienced users.
Conclusion
The end of mainstream maintenance for SAP ECC is a deadline, but it is also an opportunity. For SMEs, a well-planned SAP S/4HANA migration can simplify operations, improve data quality and provide a platform for further DX. The key is to start early, choose the right approach, keep the core clean and use a cost-effective delivery model.