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Twenty-six pages on conversion credit treatment, named-user reclassification under the new metric scheme, Digital Access reconciliation, custom-code remediation cost, the brownfield versus greenfield decision and the 2027 commercial window.
SAP has set the end of mainstream maintenance for SAP ECC at 31 December 2027, with an extended maintenance window available at a published surcharge through to the end of 2030. The 2027 date is the principal commercial driver of the S/4HANA conversion programme. Beyond that date, the buyer who has not converted faces a cost step that does not have an obvious commercial defence inside an internal capital plan.
The publisher's logic is straightforward. The S/4HANA platform is the SAP applications roadmap. The HANA database is the data architecture inside that roadmap. The Business Technology Platform is the extensibility layer. The SAP commercial position rests on the assumption that the existing ECC customer base will, over a defined window, route into one of the three commercial postures available on the new stack: brownfield conversion to S/4HANA on customer-managed infrastructure, greenfield implementation on customer-managed infrastructure, or subscription to RISE with SAP under the Premium or Premium Plus bundle.
The buyer's logic is, or should be, equally clear. The conversion is a forced commercial event with a fixed deadline. The buyer who arrives at the conversion window with a defensible position on credit treatment, named-user reclassification, Digital Access posture and custom-code remediation cost negotiates from a position of strength. The buyer who arrives without it converts at SAP's posture and the resulting commercial position determines the SAP relationship for a decade.
The conversion credit is the financial expression of the perpetual licence rights the buyer already owns. It is not, in commercial substance, a discount; it is the recognition that the buyer's existing entitlement carries over into the new platform under a defined mapping schedule.
The credit calculation runs three passes. The first pass identifies the full legacy entitlement: every line item on the ECC contract, every perpetual licence, every named-user entitlement, every engine licence, every option module. The list is rebuilt from the original contract base, not from the current support invoice, because support invoices often omit lines that have been parked or carried at reduced rates.
The second pass maps each legacy line to the S/4HANA equivalent under SAP's published mapping schedule. The mapping schedule is not symmetric. Some legacy entitlements map at one-for-one ratios; some map at fractional ratios; some map into a different metric (engine to named user, named user to FUE). The schedule is published, but it is also revised, and the version of the schedule applied at the conversion window determines the credit position.
The third pass values the credit. The S/4HANA equivalent entitlement is priced against the current S/4HANA price list, the legacy entitlement is removed, and the net of the two is the conversion credit. The credit is then applied either to the conversion contract (where the buyer is converting to on-premises S/4HANA) or to the RISE subscription fee (where the buyer is converting to RISE).
The under-stated credit is the most common failure mode in Admodum's diagnostic of S/4HANA conversion contracts. The under-statement arises from incomplete legacy entitlement records, conservative readings of the mapping schedule, or commercial decisions inside the SAP account team to net the credit against unrelated negotiation positions. The Admodum protocol re-runs the credit from the original contract base, applies the published schedule line-by-line, and surfaces the gap as a documented position before the contract is signed.
The S/4HANA named-user scheme reorganises the legacy ECC user-type hierarchy into a smaller set of S/4HANA user types. The reclassification is a material commercial event in its own right and is too often allowed to occur as an administrative by-product of the conversion.
The principal user types in the S/4HANA scheme are the Functional User (full access to S/4HANA functional capability), the Productivity User (limited transactional access), the Developer User (development environment access) and the Self-Service User (read-only or self-service access through a narrow set of applications). Each carries a different price band, and the mapping from the legacy ECC user types (Professional, Limited Professional, Employee, Worker, Self-Service, Developer, External Auditor and others) is not uniform.
The Admodum reclassification protocol runs three steps. The estate of named users is exported from the SAP USMM and LAW reports against the current ECC system. Each named user is reclassified against the actual usage telemetry, not against the legacy user-type assignment, with the consequence that users carrying the wrong user type historically are corrected at the conversion. The reclassified estate is then mapped onto the S/4HANA user-type catalogue, and the resulting requirement determines the named-user position the buyer carries into the S/4HANA contract.
SAP's Digital Access framework prices indirect access to the SAP digital core on a document basis. Nine document types are defined, each with a unit price, and the buyer's Digital Access entitlement is the sum of the documents the buyer's third-party systems consume against the SAP core in a defined measurement period.
The S/4HANA conversion is the natural moment to reconcile the Digital Access estate. The historical baseline (the document-volume baseline used by SAP to anchor the buyer's Digital Access entitlement) is the central reference point. The buyer who arrives at conversion with the historical baseline understood, documented and defended converts the Digital Access exposure at the buyer's reading; the buyer who does not converts at SAP's reading.
The nine Digital Access document types are sales documents, invoice documents, purchase documents, service-and-maintenance documents, manufacturing documents, quality-management documents, time-management documents, financial documents and material documents. Each carries a published unit price. The buyer's Digital Access requirement at the conversion window is the projected annual document volume across the nine types, priced at the corresponding unit price.
The custom-code estate is the principal cost driver of the brownfield conversion path. The S/4HANA Simplification List defines a set of legacy transactions, tables and function modules that are simplified, replaced or retired in S/4HANA. Custom code that references any of those objects must be remediated before the conversion completes.
The remediation cost is a function of the size and complexity of the custom-code base, the number of references into the Simplification List, the quality of the original code documentation, and the implementation partner's engagement model. Most buyers underestimate the cost at the start of the conversion programme; most buyers discover the true cost three to six months into the programme.
The Admodum custom-code protocol is to run the SAP Readiness Check at the start of the conversion preparation, classify every remediation against the Simplification List, scope the implementation partner against the classified estate, and treat the resulting cost as a separately negotiated programme expense rather than as a hidden component of the licence conversion.
The S/4HANA conversion path is one of two principal architectural postures. The brownfield path (system conversion) preserves the existing ECC instance, the existing customisations, the existing master data and the existing historical transactional record. The greenfield path (new implementation) starts on a fresh S/4HANA tenant with reconstructed master data, redesigned processes and migrated historical data only where it is required.
The brownfield path is preferred where the existing ECC instance is operationally healthy, the custom-code estate is contained, the master data quality is acceptable, and the business case for a process redesign does not justify the cost of a full reimplementation. The greenfield path is preferred where the ECC instance has accumulated technical debt to the point that a remediation is more expensive than a reimplementation, where the process redesign carries clear business value, or where the buyer is consolidating multiple legacy SAP instances onto a single S/4HANA tenant.
The Admodum decision tree weighs five criteria: the custom-code remediation cost, the master-data remediation cost, the process redesign value, the operational risk of a full re-platforming and the timeline against the 2027 horizon. The recommendation is not always greenfield, and is not always brownfield; the recommendation is the path that produces the lowest defensible total cost of ownership across a ten-year horizon.
RISE with SAP is SAP's principal subscription packaging of the S/4HANA stack. The bundle includes the S/4HANA Cloud Private Edition application licence, the HANA database, the hyperscaler infrastructure tenancy, a managed-services component and a defined BTP allowance. The bundle is sold at a defined commercial framework that differs materially from the on-premises licence framework.
The RISE Premium and Premium Plus tiers differ in their managed-services scope, their BTP allowance and their commercial flexibility. The Private Cloud Edition (PCE) component is the S/4HANA application licence configured for cloud delivery; the hyperscaler tenancy underneath is selected from a published catalogue of providers; the managed-services component covers infrastructure operations and basis activities.
The BTPEA bundle (the BTP Enterprise Agreement) is the BTP commercial component the buyer commits to alongside the RISE subscription. The BTPEA carries its own ramp design (analogous to the MACC ramp for Azure) with the BTP consumption converted at published rates into the BTPEA commitment.
The cost framing of RISE against on-premises S/4HANA is the central commercial decision at the conversion window. The framing depends on the conversion credit application, the BTP commitment scope, the hyperscaler infrastructure cost, the managed-services scope and the buyer's preference between operational expenditure and capital expenditure. The Admodum cost framing model normalises the postures onto a common ten-year horizon to support the decision.
The negotiation posture inside the 2027 commercial window is a function of how close the buyer is to the deadline. The buyer who arrives at the window with eighteen months of preparation time has a material negotiation position. The buyer who arrives with six months has lost most of the leverage. The buyer who arrives with three months is converting at SAP's terms.
The Admodum negotiation playbook inside the conversion window is to fix the credit position, fix the user-type reclassification, fix the Digital Access reconciliation and frame the cost across paths before SAP opens the formal conversion negotiation. The published positions become the buyer's BATNA across the negotiation. The conversion contract is signed at the position the buyer documented, not at the position SAP proposes.
The extended maintenance window through 2030 is the buyer's last commercial fallback. The published surcharge applies on top of the existing support fees and the entitlement scope is unchanged. The Admodum recommendation is to treat extended maintenance as a defensive commercial fallback rather than as a programme path, because the extended-maintenance estate carries the technical debt of the legacy stack into the post-2027 horizon without resolving the underlying conversion question.
The S/4HANA conversion paper sits inside a four-paper SAP reading list. The companion papers extend the methodology to adjacent commercial mechanics:
The methodology in this paper is the methodology Admodum has applied across more than twenty S/4HANA conversions inside the firm's engagement history. Each engagement is structured as fixed fee, contingency / gainshare or annual retainer, depending on the buyer's posture at the conversion window.
A senior Admodum advisor will walk the methodology through with your CIO, CFO, sourcing or SAP CoE team on a private call. Engagements run as fixed fee, contingency or annual retainer.