Retiring seventeen years of ERP customisation without pausing the business
An ECC landscape carrying 3,400 custom programs was approaching end of maintenance. VYNQOR delivered a clean-core greenfield S/4HANA implementation across 20+ countries in fifteen months.
A 2027 maintenance deadline is a board-level date, not an IT milestone.
This global automotive manufacturer had run SAP ECC 6.0 since 2008 across twelve legal entities. Seventeen years of accumulated customisation had produced a landscape with more than 3,400 Z-programs and custom enhancements - each individually justified, collectively a constraint on every subsequent change.
End of mainstream maintenance in 2027 converted a long-standing technical debt problem into a dated commercial risk. Meanwhile the monthly financial close was taking more than eight days, driven by siloed FI/CO data and manual reconciliation across sites - a cadence that materially limited how quickly leadership could act on financial reality.
End of mainstream maintenance in 2027 with no viable extension path for a landscape of this complexity.
An eight-day close meant leadership was steering a multinational manufacturer on materially stale financial data.
3,400+ custom programs made every upgrade a bespoke engineering exercise rather than a routine platform activity.
- Highly customised ECC landscape with 3,400+ Z-programs limiting agility and increasing upgrade complexity.
- Fragmented financial close taking 8+ days monthly from siloed FI/CO data and manual reconciliation.
- Twelve legal entities operating with divergent process interpretations.
- Growing technical debt and performance bottlenecks against a fixed 2027 maintenance horizon.
How we approached it
Greenfield was chosen deliberately: carrying seventeen years of customisation forward would have preserved the constraint the programme existed to remove.
Adopt a clean-core strategy
Business requirements were resolved against standard S/4HANA capability rather than replicated as custom code - deliberately reversing the pattern that created the original constraint.
Redesign process to platform capability
Rather than configure S/4HANA to match legacy process, requirements were reframed against best-practice process, using SAP Activate as the delivery discipline.
Make financial consolidation real-time
Universal Journal (ACDOCA) and Group Reporting eliminated the reconciliation layer between entities, restructuring the close rather than accelerating the existing one.
Instrument production for decision-making
SAC integration delivered real-time production KPI dashboards, so operational data reached decision-makers on an operational cadence rather than a reporting one.
Preserve auditability through flexible workflow
Workflows were designed to retain audit traceability across entities without reintroducing custom development.
The architecture behind the outcome
A clean-core S/4HANA architecture - standard capability at the centre, extensions kept deliberately outside it.
Measured, not estimated.
Metrics we would instrument next to extend value measurement beyond the delivered baseline. These are recommendations, not achieved results.
- Custom code footprint as a percentage of total transaction volume, tracked to protect the clean core over time
- Cost and elapsed time of the next S/4HANA release upgrade versus the historic ECC upgrade baseline
- Percentage of production decisions made against real-time SAC data rather than periodic reporting
Delivered through VynImpact™
Every VYNQOR engagement runs on the IMPACT methodology, so delivery health is visible continuously rather than reported retrospectively. This programme ran 15 months end to end.
Profiled the 3,400+ Z-program estate to establish what represented genuine differentiation versus accumulated workaround.
Reframed business requirements against standard S/4HANA capability, defining where process would change rather than the platform.
Structured the greenfield build, selective data migration approach and multi-entity rollout sequence.
Delivered the S/4HANA 2023 core with Universal Journal, Group Reporting and SAC integration.
Rolled out across 20+ countries and 12 legal entities with process change embedded ahead of go-live.
Measured close duration, inventory position and infrastructure cost against the legacy baseline.
Scope, grouped by discipline
Platform Engineering
- Greenfield S/4HANA 2023 implementation
- Clean-core architecture with custom code avoidance
- Selective data migration from ECC 6.0
- Legacy ECC and middleware decommissioning
Business Process
- Requirement redesign against standard S/4HANA capability
- Best-practice process deployment across 12 legal entities
- Harmonised finance, supply chain and manufacturing processes
Governance
- Flexible workflows with full audit traceability
- Multi-entity financial governance model
- Group Reporting consolidation framework
Automation
- Universal Journal (ACDOCA) real-time posting
- Elimination of manual inter-entity reconciliation
- Automated period-end processing
Operations
- SAC real-time production KPI dashboards
- 20+ country deployment and hypercare
- Modules deployed: FI/CO, MM, SD, PP, QM, PM, EWM, GR, SAC
Client testimonial pending approval. This engagement is available as a named reference on request.
Reference available on requestWhat made the difference
We argued for greenfield and defended it
Carrying 3,400 Z-programs forward would have preserved the exact constraint the programme existed to remove. Clean core was a strategic position, not a technical preference.
The close was restructured, not accelerated
Eight days to two is not process tuning. Universal Journal removed the reconciliation layer between entities entirely.
Fifteen months across twelve legal entities
Multi-entity, multi-country greenfield programmes routinely run longer. Delivery discipline and process-to-standard resolution kept scope from expanding into custom build.
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