Every number in a Serre business case comes from transparent math you can read — formulas with inputs you control. The AI helps you draft formulas, suggest inputs, and write the narrative, but you review every value before it lands in the case.
From drivers to a total#
Each value driver in your case carries a formula — for example:
dispatches_per_month × cost_per_dispatch × deflection_rate × 12
Serre evaluates each driver with the inputs you entered and adds the results into the case's annual benefit. On the Calculate step, each driver shows its formula and its yearly value. Click "Edit inputs" on a driver to see and edit the inputs behind it.
If a driver can't be computed — say, an input is missing — Serre names it and won't save the calculation until you fix it.
The headline metrics#
The case header shows Annual benefit, ROI, and Payback. The Live estimate on the Calculate step adds NPV.
- Annual benefit — the summed yearly value of all the drivers on the case.
- ROI — return on investment: annual benefit compared with the buyer's first-year cost. Next to every ROI figure, Serre says what it means — for example, "$3.00 back per $1 spent · break-even at 100%".
- Payback — how many months of benefit it takes to cover the first-year cost.
- NPV — net present value: the benefit minus the costs over the deal term, with future money discounted to today's value. The label shows the term, like NPV (3yr).
The investment side is yours to set on the Calculate step: Deal term (months), Annual cost, implementation, and other one-time or ongoing costs.
Gross or net ROI#
By default Serre shows gross ROI: $300,000 of benefit against $100,000 of cost reads as 300%, and 100% is break-even. Some teams prefer net ROI, where the same case reads as 200% and break-even is 0%.
An admin or the workspace owner can switch this under Settings → Case standards → ROI reading. Only the way ROI is written changes, never the underlying numbers. Cases already calculated keep the reading they were calculated in until you recalculate them.
Why you get a range, not just one number#
A single-point ROI invites a single question: "says who?" So alongside the expected result, Serre stress-tests the case across the plausible range of each input. On the Deliver step, the annual benefit appears as three outcomes:
- Conservative. Things go worse than expected.
- Expected. The middle of the range.
- Upside. Things go better than expected.
Leading with the conservative number is usually the strongest move in the room: if the case clears the bar in the conservative case, the hardest question is already answered.
A note on credibility#
A case that costs the buyer more than it returns is below break-even. Serre won't let you deliver it until you raise the benefit or lower the investment.
At the other end, Val Review flags results that are technically correct but hard to defend — a very high ROI can read as un-credible to a CFO even when the math holds. For those cases Val may suggest the Benefits only presentation mode, which hides ROI and payback and leads with the annual benefit range instead.