Brownfield migration cost versus RISE conversion cost.

The cost of moving from SAP ECC to S/4HANA differs structurally between a brownfield conversion on the buyer hyperscaler of choice and a RISE conversion into the SAP Cloud Private Edition. The two pathways carry different SI partner cost profiles, different parallel run obligations, different change management overheads, and different post conversion stabilisation costs. The headline migration cost for both pathways looks similar in the SAP supplied business case. The actual migration cost across the firm engagement base shows a structural differential, with hidden lines that shift between the two options. This article documents the comparison line by line, with the cost ranges from the engagement base and the negotiation surfaces that affect each line.

The SI partner cost profile

The SI partner cost is the largest single line in either migration option, and the cost profile differs between the two pathways. A brownfield conversion to S/4HANA on the buyer hyperscaler typically engages the SI partner across the full migration scope, from system landscape design through to post conversion stabilisation. The SI partner cost on a brownfield conversion runs between thirty and seventy percent of the total migration budget, depending on the system size, the customisation complexity, and the geographic footprint.

A RISE conversion carries a different SI partner profile. The SAP Cloud Private Edition platform absorbs a portion of the work that the SI partner would carry on the brownfield side, including the infrastructure provisioning, the SAP basis administration, and the platform patching. The SI partner cost on a RISE conversion typically runs between twenty and fifty percent of the total migration budget, with the SAP supplied platform work absorbing the differential. The differential is real, but it is not free, because the SAP supplied work is priced into the bundled subscription rather than appearing as a separate line.

The buyer side discipline is to compare the all in SI plus platform cost on both sides rather than the SI line in isolation. The brownfield comparison adds the SI cost plus the hyperscaler reserved capacity plus the internal basis administration. The RISE comparison adds the SI cost plus the bundled SAP subscription, with the platform component implicitly priced inside the bundle. Across the firm engagement base, the all in comparison shows a smaller differential than the SI line in isolation would suggest, with the RISE option typically running between three and twelve percent below the brownfield option on the year one migration cost line.

Parallel run obligations on both sides

The parallel run cost is the cost of operating both the existing ECC system and the target S/4HANA system through the migration window. The parallel run obligation differs between the two pathways. On the brownfield side, the parallel run is operated by the buyer, with the cost reflecting the buyer infrastructure and operational staffing across the window. On the RISE side, the parallel run can be operated as a combination of the existing ECC inside the buyer infrastructure and the target S/4HANA inside the RISE bundle, with the RISE side priced at the standard subscription rate during the parallel period.

The parallel run window varies by approach and by system complexity. A big bang cutover compresses the parallel run to a defined cutover weekend plus a stabilisation period of two to four weeks. A phased rollout extends the parallel run across multiple months, with the modules transitioning in sequence. The parallel run cost on the brownfield side typically runs between two and six percent of the total migration budget. The parallel run cost on the RISE side typically runs between three and eight percent, because the RISE subscription is priced at the full rate during the parallel period.

The buyer side counter on the RISE side is to negotiate a discounted parallel run rate inside the RISE contract. The SAP account team will resist the discount because it reduces the year one revenue, but it is consistently conceded under executive escalation when the parallel run window is documented as a hard requirement. The negotiated parallel run rate typically sits between fifty and seventy percent of the steady state subscription rate, with the discount applying for a defined period that matches the parallel run obligation.

Change management and the user side cost

Change management is the cost of preparing the user community for the S/4HANA functional and user interface changes. The change management cost is largely independent of the deployment model, because the S/4HANA functional surface is the same in both RISE and brownfield. The cost is driven by the user count, the role complexity, the geographic distribution, and the language requirements. Change management typically runs between eight and eighteen percent of the total migration budget, with the spread driven by these four variables.

The change management cost differs slightly between the two pathways on the user interface side. The RISE option includes the SAP Fiori user interface in the bundled subscription, with the Fiori catalog updated continuously by SAP. The brownfield option also runs Fiori, but the catalog updates are managed by the buyer, with the corresponding internal staffing cost. The differential is typically small, in the range of one to three percent of the change management budget, with the RISE option running slightly lower on the user interface line.

The change management work is also affected by the customisation reduction discipline. S/4HANA encourages the reduction of legacy ECC customisations, and the discipline of customisation reduction runs through both pathways. A brownfield conversion that preserves the legacy customisations carries a higher change management cost because the user community sees a system that behaves like the existing ECC with some structural changes. A RISE conversion typically forces a higher level of customisation reduction because the Cloud Private Edition platform constrains the depth of permitted customisation. The forced reduction raises the change management cost on the RISE side but reduces the post conversion operating cost.

Custom code remediation and the customisation boundary

Custom code remediation is the cost of converting the legacy ECC ABAP customisations to the S/4HANA programming model. The cost is driven by the volume of custom code in the existing ECC, the complexity of the customisations, and the boundary of permitted customisation on the target system. A brownfield S/4HANA conversion permits the full ABAP customisation surface, with the migration tools supporting the conversion of most legacy customisations to the S/4HANA programming model.

A RISE Cloud Private Edition conversion permits a narrower customisation surface, with key user extensibility and developer extensibility constrained to the SAP supported framework. The boundary forces a portion of the legacy customisations to be redesigned rather than converted, with the corresponding additional cost. Across the firm engagement base, the custom code remediation cost on a brownfield conversion typically runs between five and fifteen percent of the migration budget. The same cost on a RISE conversion typically runs between eight and twenty percent, with the differential driven by the redesign overhead at the customisation boundary.

The customisation reduction discipline mitigates the differential. A buyer who reduces the legacy customisations before the migration starts faces a smaller remediation cost on both sides. The discipline is the same on both sides. The legacy customisations are audited, the business value of each is assessed against the standard S/4HANA functionality, and the customisations that do not justify the maintenance cost are decommissioned in advance. The reduced customisation footprint compresses the remediation cost differential between the two pathways, with the RISE option becoming more competitive on this line as the reduction work progresses.

Infrastructure setup and the hyperscaler choice

Infrastructure setup is the cost of provisioning the target S/4HANA environment, with the underlying compute, storage, network, backup, and disaster recovery configuration. On the brownfield side, the infrastructure setup is the buyer responsibility, with the cost reflecting the hyperscaler reserved capacity contract, the network design work, the disaster recovery configuration, and the initial provisioning cost. On the RISE side, the infrastructure setup is included in the bundled subscription, with the provisioning timeline driven by the SAP and hyperscaler joint runbook.

The infrastructure setup cost on the brownfield side typically runs between three and ten percent of the migration budget, with the spread driven by the disaster recovery configuration choice and the geographic footprint. The same cost on the RISE side is implicitly priced in the bundled subscription, which means it does not appear as a discrete line in the migration budget. The implicit pricing is the source of the bundled hyperscaler markup, which runs at between eighteen and thirty two percent above the open market reserved capacity rate.

The buyer side discipline is to compare the explicit brownfield infrastructure cost against the implicit RISE infrastructure cost, with the implicit cost calculated against the open market reserved capacity rate plus the bundled markup. The comparison shows the true differential between the two pathways. A buyer who selects the hyperscaler region carefully on the brownfield side can drive the infrastructure cost below the implicit RISE cost. A buyer who accepts the default RISE region without question pays the bundled markup across the full seven year term, not just in the year one migration.

Post conversion stabilisation and the warranty period

Post conversion stabilisation is the cost of operating the new S/4HANA system through the initial production period, with the SI partner and SAP supporting the issue resolution as the system reaches steady state. The stabilisation period typically runs between three and twelve months from cutover, depending on the system complexity and the user community size. The cost during this period reflects the residual SI partner cost, the SAP issue resolution support, and the internal staffing required to manage the post cutover backlog.

On the brownfield side, the post conversion stabilisation is governed by the SI partner warranty period, which typically covers a defined set of issues at no additional cost across a three to six month window from cutover. Issues beyond the warranty period are billed at the prevailing professional services rate. The post conversion stabilisation cost on the brownfield side runs between two and seven percent of the migration budget, with the warranty period absorbing the bulk of the in scope work.

On the RISE side, the post conversion stabilisation is governed by the included RISE support coverage, which covers a defined set of issue types under the bundled support scope. The coverage is wider than the brownfield warranty in some categories and narrower in others, with the differential driven by the in scope definition. The post conversion stabilisation cost on the RISE side runs between three and nine percent of the migration budget, with the spread driven by the support coverage scope ratio. The buyer side counter on the RISE side is to widen the in scope definition during the stabilisation period through a dedicated stabilisation schedule in the RISE contract.

Compare the all in cost, line by line

The brownfield versus RISE migration cost comparison resolves on the all in cost line by line, not on the headline migration budget. The SI partner cost line, the parallel run line, the change management line, the custom code remediation line, the infrastructure setup line, and the post conversion stabilisation line each carry different weights between the two pathways. The buyer side discipline is to model each line on both sides at the same scope, with the same assumptions, and to read the comparison against the contract surfaces that affect each line.

Across the firm engagement base, the all in migration cost comparison resolves in favour of brownfield in approximately forty percent of deals, in favour of RISE in approximately thirty percent of deals, and in favour of a hybrid model in approximately thirty percent of deals. The differential between the two pathways on the migration budget is typically smaller than the SAP supplied business case suggests, in the range of plus or minus eight percent. The decision turns on the seven year operating cost differential rather than on the migration cost differential, with the migration cost as the entry point into the broader comparison rather than the deciding line in the comparison.