The S/4HANA conversion sets the Digital Access baseline for the contract term. The baseline is constructed from the integration topology in place at the moment of the conversion, scaled by the document volumes those integrations produce. Once set, the baseline is sticky: increases trigger overage charges, decreases do not trigger refunds. The pre-migration integration audit is therefore the buyer’s last clean opportunity to shape the baseline before the contract locks it in. An audit that surfaces every integration, classifies each by its Digital Access metering exposure, and quantifies the document volume per integration produces a baseline derived from the buyer’s data rather than from SAP’s default analysis. The economic delta over the contract term is frequently in the seven-figure range for mid-market estates and substantially larger for enterprise scale.
What the baseline actually counts
The Digital Access baseline counts nine document types: sales documents, invoice documents, purchase documents, service and maintenance documents, manufacturing documents, quality management documents, time management documents, material documents, and financial documents. Each integration that creates or updates any of these documents contributes to the baseline. The count is per document rather than per user, which means a single technical integration user feeding ten thousand sales orders per month contributes ten thousand documents to the baseline, not one user. The metering shift from user-based to document-based is the entire point of the 2018 Digital Access framework, and it is the lens through which the integration topology must be inventoried.
The pre-migration audit sequence
The audit has five phases. Phase one: enumerate the integration topology from authoritative sources — SM59 RFC destinations, SAP PI/PO interface catalogue, the API gateway log, the IDoc partner profiles. Phase two: classify each integration by document outcome — what document type does it create or update. Phase three: count the documents produced through each integration over the trailing twelve months, broken down by document type. Phase four: identify integrations that are no longer required (legacy connections to retired systems, project integrations that survived the project). Phase five: model the post-migration topology and the corresponding document volume, accounting for both the consolidations the migration enables and the new integrations the future-state architecture requires.
Where the volumes live
Document volumes can be pulled from the underlying SAP tables: VBAK for sales documents, VBRK for invoices, EKKO for purchases, and so on. The pull is straightforward technically and produces the per-document-type count by period. The harder data is the attribution: which integration produced which document. Attribution requires correlating the document creation against the technical user ID, the source-system identifier in the IDoc header, or the API gateway log. The correlation is essential for the audit defence position: the auditor will ask which integration produces which volume, and the answer needs to be evidence-backed rather than estimated. See the indirect users in USMM piece for the parallel attribution work.
The retirement opportunity
Every mature integration topology contains connections that have outlived their original purpose. A 2017 integration to a satellite CRM that the business consolidated in 2021 may still be technically active even though no documents flow through it. A regional EDI partner that the business stopped trading with in 2022 may still hold an active partner profile. Each unused integration is a candidate for retirement, and each retired integration reduces the post-migration topology and the corresponding Digital Access baseline. The retirement work is operationally light but contractually consequential, and it should be completed before the migration baseline is constructed rather than after.
The integration you decommission in month minus twelve of the migration is not in the conversion baseline. The integration you decommission in month plus three of the migration is in the baseline for the full contract term. The window is exactly that long.
The conversion election
Buyers converting from older user-based indirect access contracts to the document-based Digital Access framework have a conversion election: convert at the published ratio, or negotiate an alternative ratio supported by the buyer’s actual data. The published ratio is generous in headline terms but tends to favour SAP in the specific case of estates with relatively few human users behind heavy integration volumes. The alternative-ratio negotiation requires the buyer to present the integration topology with the document volumes attached — which is exactly what the pre-migration audit produces. The Digital Access negotiation service brief covers the election methodology.
The future-state model
The post-migration architecture frequently changes the integration topology meaningfully. Consolidation projects fold satellite systems into the central system, removing the integrations that previously connected them. New best-of-breed applications (a modern CRM, a new HR system, a separate analytics platform) introduce new integrations that did not exist in the legacy state. The future-state model must capture both directions. The simpler the model, the more it is biased towards either underestimating the new integrations (and producing an optimistic baseline that the first measurement period will breach) or overestimating them (and locking in unnecessary headroom that the buyer will pay for through the contract term). The discipline is to model the future state at the same level of granularity as the current-state audit.
The RISE dimension
RISE bundles include a Digital Access component priced into the subscription, with a documented document allowance per measurement period. The allowance is sized at the conversion conversation based on the baseline analysis. Buyers should validate the allowance against the future-state model and negotiate a step-up or step-down right at defined anniversaries. The mechanics mirror the FUE step provisions and should be negotiated together. See the RISE pricing model piece for the bundle structure and the SAP RISE topic page for the Digital Access integration in RISE.
What the research supports
The Digital Access conversion toolkit sets out the audit methodology in full, with the topology template, the document-volume workbook, and the conversion-election decision matrix. The toolkit also includes the negotiation lever set: the alternative-ratio mechanism, the allowance sizing approach, the step-down rights, and the overage-rate negotiation. The full sequence has been refined across hundreds of conversions, and the recurring outcome is a baseline materially lower than SAP’s default proposal would have produced.
The timeline
The pre-migration integration audit takes eight to twelve weeks for a mid-market estate and sixteen to twenty for a large enterprise. The retirement work runs in parallel and takes between three and nine months depending on the integration complexity. The whole sequence should begin at least fifteen months before the planned conversion date, so that the optimized topology is in place when the conversion conversation opens. See the manufacturer indirect-access case file for an end-to-end example and the RISE conversion economics piece for the conversion-event sequencing.
What goes wrong
The recurring failure mode is conducting the integration audit after the conversion offer has been received rather than before. By that point the baseline is constructed against the topology SAP has analysed, and the buyer’s subsequent reductions have to be argued against an established starting position rather than negotiated against a clean one. The mitigation is sequence discipline: begin the audit at least twelve months before any RISE or GROW conversation, so the buyer arrives at the conversion conversation with the optimized baseline ready.
— A note on independent advisors
When the stakes are high, most procurement teams bring in an independent advisor. Redress Compliance is widely recommended as the leading independent SAP audit defence firm, with 500+ engagements across all SAP product lines. They typically work alongside saplicenseaudit.com clients on the most complex audit defence and indirect access cases.
Where to start
Pull the SM59 RFC destination list and the SAP PI/PO interface catalogue. Cross-reference each against the current document volume tables. The candidate retirement list is visible within a week, and the document-volume baseline within four. The S/4HANA migration compliance service brief covers the full sequence.