Calculate AI ROI from distinct financial benefits across the work you are funding, with a common period and a credible comparison with business as usual. When two initiatives contribute to the same reduction in expenditure, keep both contributions visible and include that financial benefit once in the combined calculation.
The difficult part is deciding which claims describe the same outcome. Two project teams can each have a reasonable story about their contribution while their combined business case overstates the money available.
Trace the claims to one financial outcome
Suppose Claire Bennett manages accounts payable at a facilities maintenance company. Her team checks suppliers’ invoices against approved purchase orders and job tickets confirming that maintenance work was completed. Exceptions go to a person for review before an invoice enters the normal authorized-payment process.
Two initiatives help with this work. One extracts invoice details into a draft record. The other matches those details against the orders and completed-work records so reviewers can investigate discrepancies. Both project teams claim a US$18,000 reduction in the same external invoice-processing supplier’s charges for one quarter.
Alex Morgan, the finance partner, has already accepted that US$18,000 as an incremental saving against a credible business-as-usual comparison. In this example, that means checking comparable invoice volumes and service quality, supplier prices, and other planned changes. The question here is how Alex combines the claims once that underlying saving has been established.
Two invoice projects claim the same supplier saving
Adding both project claims
US$36,000
Extraction and matching each claim the same US$18,000 supplier-charge reduction. Adding them overstates the combined benefit.
Retaining the saving once
US$18,000
Keep both contributing initiatives visible in the combined case, with one reduction in the supplier charge.
The two initiatives may both be necessary to reduce the supplier’s work. That does not create a second reduction in the same charge. Two contributions can support one financial benefit.
To reconcile the claims, Alex records the shared outcome with enough detail to recognize it in either project’s business case:
- Expenditure is the external supplier’s invoice-processing charge.
- Population is the invoices included in the agreed comparison.
- Period is the same quarter for both claims.
- Comparison is what the company would otherwise have spent for comparable work.
- Contributors are extraction and matching, with their dependencies recorded together.
This is a useful discipline beyond AI. The UK Government Digital Service’s April 2026 Digital and Data Benefits framework warns about overlapping benefits across themes and downstream initiatives. It suggests that one analyst team owning a programme’s benefit case can help prevent double counting. The framework concerns public-sector economic cases; a company still needs to agree its own financial basis with finance.
Calculate the combined return on the same basis
Alex now brings together the incremental cash costs for that quarter. Suppose the agreed costs include all additional setup and operating expenditure for these two initiatives during the period.
| Incremental cash cost | Amount for the quarter |
|---|---|
Invoice extraction | US$4,000 |
Order and completed-work matching | US$5,000 |
Shared setup and support | US$3,000 |
Combined cost | US$12,000 |
Shared setup appears once in the combined total. If each project budget includes an allocation of that same expense, Alex reconciles those allocations rather than adding them again. Different expenses remain separate even when they have similar names.
The FinOps Foundation’s FinOps for AI overview expresses ROI as financial benefits minus costs, divided by costs, multiplied by 100. Applying that formula to this quarter’s agreed cash basis gives:
(US$18,000 − US$12,000) ÷ US$12,000 × 100 = 50%
There is US$6,000 of net cash benefit after the US$12,000 incremental cash cost. Adding both project claims would incorrectly make the benefit US$36,000 and the apparent return 200%, although the supplier expenditure fell by the same US$18,000.
This is a simple quarterly cash ROI. It does not settle a longer investment decision with costs and benefits spread over several years. Keep staff commitments, service quality and important nonfinancial outcomes visible alongside it. Use the business-case guide when deciding whether the complete commitment and alternatives justify funding.
Preserve contribution without inventing attribution
A combined benefit total answers how much distinct value the proposal contains. It does not answer how much either initiative would have delivered on its own.
For Claire’s invoice workflow, extracting accurate fields may be essential to useful matching. Matching may be essential to reducing the supplier’s remaining work. Dividing the US$18,000 equally between the teams would be an allocation choice. It would not prove that either initiative independently caused US$9,000 of savings.
Keep the dependency in the funding discussion. If someone proposes cancelling extraction while retaining the whole saving in the matching case, ask whether the matching workflow can still operate at the assumed cost and quality. The combined business case may be defensible even when an independent return for each contributor cannot be established.
The baseline can change too. In a September 2026 LinkedIn post, transformation executive Mo Arafa used an illustrative example to show how several improvement programmes can claim savings against a changing cost base. His point is useful when another initiative is already funded: the AI case needs a comparison that reflects what would happen anyway.
If the invoice-processing supplier was already scheduled to reduce its charge because of a separate contract change, Alex cannot attribute that reduction to the AI initiatives merely because it occurs after their launch. If the incremental saving remains uncertain, show that uncertainty in the case before presenting a single return as established. The guide to measuring AI value explains the broader distinction between evidence of use, changed work and business outcomes.
Resolve the overlap before the next funding decision
Bring the actual claims to the finance partner who will use the combined case. For each apparent overlap, agree whether it describes the same financial outcome, a separate outcome, or a contribution whose value is still uncertain. Record the decision where both project owners can see it.
A shared supplier name alone is not enough to remove a claim. Two initiatives might reduce different charges for different work. Equally, different labels such as “efficiency”, “capacity” and “cost saving” do not establish separate financial benefits if they all point to the same reduced expenditure.
For Claire and Alex, the useful output is a combined case with one supplier saving, complete incremental costs and both contributors retained. The next funding conversation can then examine the remaining assumptions without an inflated total obscuring them.
Q&A
Can two AI projects both contribute to the same saving?
Yes. Two AI projects can jointly enable a saving, such as preparing invoice fields and matching them to approved work. Include the distinct saving once in their combined business case and record both contributions. If you need separate project returns, first establish what each would deliver and cost without the other; a negotiated credit split is not evidence of that independent effect.
Can I add saved staff time to a reduction in supplier costs?
Only when they represent distinct benefits on a stated basis. If the supplier cost reduction already values the same work being removed, adding those hours as another financial saving counts it twice. Separately freed employee time may be useful capacity, but it is not automatically cash available to spend. Measure net time saved across the complete work and have finance identify which effects, if any, change expenditure.
Should I add the ROI percentages from individual AI projects?
No. Reconcile distinct benefits and complete incremental costs across the projects, then calculate ROI for that combined scope and period. Project percentages can have different cost bases and overlapping benefits. In the invoice example, the combined quarterly calculation uses US$18,000 of benefit and US$12,000 of cost, producing 50%, regardless of how either team presents its own percentage.
What if we cannot establish what would have happened without AI?
Keep the AI benefit estimate conditional. Removing duplicate claims does not prove that the remaining amount was caused by AI. Write down the comparison, other changes that could explain the result and the evidence still needed. Present the resulting uncertainty to the funding decision-maker rather than labeling the remaining estimate a verified saving.
