Cost is computed per tool, never from memory: each price with its source, the 12- and 24-month TCO by arithmetic, and the projection checked later against the invoice that actually arrived.
The problem
The cost estimate is born on a slide, with no source and no memory. Nobody knows where the number came from, nobody comes back to check whether it happened, and the gap between projected and real only shows up once it is already a budget problem.
Each cost item declares its source: vendor website, project baseline, estimate with the client. The TCO is computed by the renderer. And the story does not end with the document: when the invoice arrives, projected and real meet in the track record.
How it works
One-off and monthly costs enter per item, with assumptions and source. The 12- and 24-month TCO is computed in code over the table: the model cannot write a total the sum does not support.
With more than one scenario, a recommendation is mandatory. Comparing without concluding hands the decision back to whoever asked for help, and the engagement exists for the opposite.
Analytics layer: monthly costs
BigQuery + BI scenario · source declared per price
| Item | Monthly cost | Source |
|---|---|---|
| Storage and querying | R$ 1,200 | vendor website |
| BI tool, 25 users | R$ 1,050 | vendor website |
| Light orchestration | R$ 350 | estimate with the client |
| Monthly total | R$ 2,600 |
TCO: R$ 37,800 over 12 months · R$ 69,000 over 24 months (R$ 6,600 setup + recurring)
The TCO is the renderer’s arithmetic over the table, never a number the model wrote from memory.
The month’s invoice comes in and is compared with the projection: the deviation shows per month, inside or outside the 20% band, and the project history shows which way the error leans.
That is what separates a projection from a commitment: whoever publishes their own deviation thinks twice before projecting optimism.
Recommended against measured
Analytics layer · 4 months since rollout
| What was claimed | Projected | Measured | Deviation |
|---|---|---|---|
| Monthly cloud cost | R$ 2,600 | R$ 2,840 | +9.2% |
| Main dashboard query | < 2.0 s | 1.4 s | within |
| Daily ingestion | < 15 min | — | not measured |
| Assumption: volume below 1 TB | — | 61 GB | holds |
Cost accuracy on this project: within plus or minus 20% in 3 of 4 months, biased low.
Under the hood
What keeps the cost analysis from becoming a slide.
What comes next
Weighted criteria, justified scores, and each option declaring how much it costs and how long it takes to leave it within 18 months.
See it from the inside →Track recordProject track recordProjected cost against the real invoice, assumptions with state, open objections and the environment’s drift, in one place.
See it from the inside →ProofMachine verificationScripts executed on a disposable PostgreSQL, business questions answered by query, and the seal showing what was and was not verified.
See it from the inside →Paste the structure, get the most serious findings in about two minutes, and decide later whether an engagement is worth opening. No account, no card.