How depreciation rules affect RISE TCO comparison.

Two finance teams can model the same RISE with SAP proposal against the same brownfield S/4HANA alternative, use the same input numbers, and produce TCO conclusions that differ by twenty percent or more. The variable that explains the gap is rarely the unit prices. It is depreciation. The accounting treatment of on premise capital expenditure, the amortisation of perpetual licences already on the books, the residual book value of existing infrastructure, and the treatment of cloud subscription expense all flow through different lines of the income statement on different time horizons. A buyer who builds a TCO model without resolving depreciation methodology first is comparing two numbers that are not actually comparable. The work to make them comparable is procedural, technical, and the single highest leverage move in early stage RISE evaluation.

01.Why depreciation dominates the comparison

RISE with SAP is sold as operating expense. The annual subscription is fully expensed in the year it is incurred. There is no asset on the balance sheet, no depreciation schedule, no residual value at the end of the term. The income statement impact is linear, predictable, and immediate.

Brownfield, by contrast, mixes capital and operating expense across categories that depreciate on different schedules. Server hardware depreciates over three to five years. Storage depreciates over five to seven. Network equipment over five. Software licences, where capitalised, depreciate over the useful life agreed with auditors, often five to seven years. Implementation costs may be capitalised and amortised over the asset's life or expensed as incurred, depending on the jurisdiction and the accounting policy.

The mix creates a timing mismatch. The brownfield estate is heavily front loaded on cash but back loaded on income statement impact through depreciation. RISE is flat on both. When the comparison is done on a cash basis, brownfield typically looks more expensive in years one through three and cheaper in years five through seven. When the comparison is done on a profit and loss basis, the shape flips. Both views are accurate. Neither is a complete picture by itself.

The CFO who signs the RISE deal needs to understand which view the executive sponsor has internalised, because the two will produce different decisions on the same facts.

02.The treatment of existing perpetual licences

Most enterprises evaluating RISE today already own perpetual SAP licences with material undepreciated book value. The treatment of that book value on conversion to RISE is the second variable that swings the TCO comparison. SAP frames the conversion as a credit against the new subscription. The credit is real, but it is not always at full book value, and the offset is typically applied over the contract term rather than as a single year reduction.

The accounting consequence depends on how the perpetual asset is treated on the books at the moment of conversion. If the asset is impaired, the write down flows through the income statement in the year of conversion, often producing a material one off charge that the audit committee may want to flag in advance. If the asset is reclassified rather than impaired, the depreciation schedule continues, which can produce a year of double counting where both the subscription and the depreciation hit the same period.

The buyer side discipline is to model both treatments explicitly. The base case assumes impairment in the conversion year. The alternative case assumes reclassification with continued depreciation. The two cases produce different total cost numbers and different timing profiles for the cost. The decision on which case is the right model is an accounting decision that needs to be made jointly with the audit team, not assumed by procurement.

Conversations with SAP about the credit value need to be calibrated to whichever case the audit team confirms. A credit that looks attractive against impairment may look thin against reclassification, and vice versa.

03.Hyperscaler infrastructure pass through

RISE with SAP includes a hyperscaler infrastructure layer that SAP procures and resells. The infrastructure cost is opex from the buyer's perspective, but the underlying hyperscaler contract sits between SAP and the cloud provider, and the buyer rarely sees the unit economics directly. The opacity matters for TCO because a brownfield comparison that includes self managed hyperscaler infrastructure can be built with full visibility into reserved instance pricing, savings plan structures, and hardware refresh schedules.

The depreciation question becomes: how does the buyer model the seven year cost of hyperscaler capacity if the brownfield case is built and operated by the buyer rather than packaged inside RISE. Hyperscaler reservations are typically modelled on a three year horizon because that matches the standard reserved instance commitment length. Beyond three years, the model needs to assume either a renewal at then current pricing or a refresh that triggers migration cost.

The disciplined approach is to build the brownfield case with explicit reservation tiers, explicit refresh assumptions, and explicit treatment of any committed spend agreements with the hyperscaler. The RISE case is then modelled as a packaged equivalent. The comparison line is the all in seven year cost of capacity plus the operational headcount required to manage it. Without that explicit treatment, the brownfield case will appear artificially cheap because the hidden operational overhead is not surfaced.

04.Migration and implementation cost amortisation

Migration cost is the third lever. A brownfield to RISE conversion requires implementation work. A greenfield S/4HANA implementation also requires implementation work. The two are not equivalent in either scope or cost, but both produce expenses that need to be allocated across the seven year horizon to produce a comparable TCO.

The accounting question is whether to capitalise the implementation cost or expense it as incurred. The answer depends on jurisdiction and on the specific nature of the work, but the most common pattern is to capitalise the work that produces a long lived asset such as a new ERP configuration, and to expense the work that is consumed in the year of delivery such as training, change management, and project management.

The capitalised portion is then amortised over the useful life. For a RISE implementation, that life is typically the contract term, which means seven years. For a brownfield implementation, the life is often longer, typically ten years, which spreads the cost across a wider window and reduces the annual income statement impact.

The TCO comparison needs to use a single amortisation horizon across both cases. The standard choice is seven years, matching the RISE term. The brownfield case is then amortised on the same window even if the useful life would otherwise be longer. The choice is conservative against brownfield, but it produces a comparable number, which is the point of the exercise.

05.Tax treatment and discount rate

Depreciation interacts with tax. Capital expenditure produces depreciation deductions that reduce taxable income. Operating expense produces immediate deductions. The net effect on cash flow depends on the corporate tax rate, the timing of the deductions, and the discount rate applied to future cash flows in the present value calculation.

A robust RISE TCO model needs to express all numbers on an after tax basis. The depreciation tax shield from the brownfield case is meaningful, sometimes worth between three and seven percent of the headline brownfield TCO. The opex tax shield from RISE is equivalent in proportion but distributed differently across years.

The discount rate is the second tax adjacent variable. A higher discount rate makes back loaded costs less significant in present value terms, which favours RISE because RISE costs are flat across years. A lower discount rate increases the present value of out year costs, which can favour brownfield where the costs decline as depreciation runs off.

The standard discipline is to model the comparison at the corporate weighted average cost of capital, then run sensitivity at plus and minus two hundred basis points. The sensitivity range reveals how much of the apparent RISE advantage is real and how much is an artefact of the discount rate choice.

06.Building a comparable model in practice

The final discipline is the model template. A workable RISE versus brownfield comparison sits on a single spreadsheet with three sheets. Sheet one is the input assumptions, including unit prices, depreciation schedules, tax rates, and discount rates. Sheet two is the brownfield model, with every cost line allocated to the correct year and treated appropriately for capital or operating expense. Sheet three is the RISE model, built to mirror the brownfield structure so the comparison flows line by line.

The output is a seven year TCO number for each case, on both a cash basis and an income statement basis, expressed after tax and discounted to present value. Each version of the output tells a different story, and each story needs to be presented to the audit committee, the board, and the operating leadership in the right format for the audience.

The model is owned by finance, not by IT. The procurement team uses the model as input to negotiation, but the model itself is built and maintained by the controller's office. The discipline matters because the model will be questioned during board review, and the answers need to come from the team that signed off on the depreciation methodology, not the team that ran the SAP conversation.

Building the model takes between three and six weeks for an enterprise of any size. The work is worth doing once. The comparison the model produces becomes the foundation for every subsequent conversation about RISE economics, both internally and with SAP.

Two finance teams can model the same RISE proposal, use the same numbers, and reach conclusions that differ by twenty percent. The variable that explains the gap is depreciation methodology, not unit pricing.

07.Conclusion

RISE with SAP changes the shape of the SAP cost line on the income statement. Whether it changes the total cost depends on a series of accounting choices that have nothing to do with the SAP negotiation itself. The buyer who resolves depreciation methodology, perpetual licence treatment, infrastructure pass through, amortisation horizon, and discount rate before producing a TCO number will produce a number that holds up under audit scrutiny and board review. The buyer who skips that work will produce a number that is contested in the first executive meeting and abandoned in the second. The work to make the comparison comparable is the work that makes the RISE decision defensible.