Financial Model Audit Engine (FMAE)
Executive Summary
Key Takeaways
- ✓ FMAE applies a fixed, versioned set of structural rules to a financial model and produces the same output on the same input every time.
- ✓ The engine tests model structure and mechanics, such as circular references, hardcoded values, and broken links, not the reasonableness of assumptions or accounting judgment.
- ✓ FMAE is not sold as standalone software; it is the common technology beneath the nine packaged Oxxon Advisors products.
- ✓ Determinism and provenance make the engine's output reproducible, which is an evidentiary property as much as a technical one.
- ✓ Every engine run produces a coverage statement disclosing plainly what was and was not analysed.
Purpose¶
FMAE is a deterministic, rule-based engine that tests the structural integrity of Excel-based financial models. It applies a fixed, versioned set of structural rules systematically across a model and produces findings, together with a coverage statement describing exactly what was and was not analysed. FMAE is the platform's engine and funnel: it is priced to convert clients into one of the nine packaged engagement products, never to maximise standalone engine revenue, and it never appears as a peer revenue line alongside those products.
Who It Is For¶
FMAE itself is not purchased directly. It is the technology consumed by every one of Oxxon Advisors' nine engagement products, and is relevant to model developers, advisory firms, and lenders as the mechanism behind the deliverables those products produce, rather than as a tool acquired on its own.
Problems Solved¶
- Manual structural review of a financial model is slow, inconsistent between reviewers, and not independently reproducible.
- Reviewers need a defined, repeatable methodology applied to every formula and structural element, rather than a sample selected at the reviewer's discretion.
- Stakeholders relying on a model's structural soundness need a clear statement of what was actually checked, not an implied but undisclosed scope.
- Structural findings need to be kept separate from commercial and accounting judgment, so that a structural opinion is never mistaken for an assessment of whether a model's assumptions are realistic.
Workflow¶
FMAE runs a defined rule pack against a financial model in a single pipeline execution. The engine identifies structural elements, such as named structures, dependency links, and circular regions, and tests them against its rule set. The result is a set of findings with associated evidence and a coverage object stating what was analysed. This engine run is the common step underneath every product in the suite; what differs between products is the deliverable template applied to the same underlying facts, the turnaround commitment, and whether a human reviewer's opinion is layered on top of the structural output.
Outputs¶
FMAE itself produces findings, coverage, and provenance data, the raw material consumed by every product's deliverable template. It does not, on its own, issue a client-facing report; the report format, from a full structural review to a committee panel, a version diff, or an audit-evidence pack, is determined by which of the nine products the engagement belongs to, each described on its own page.
Continue Reading¶
Related Products¶
- FMAE Product Overview
- Independent Structural Model Review
- Committee Readiness Pack
- Documentation & Handover Pack
Related Pillars¶
Related Comparisons¶
How OXXON tests thisRun a free structural check with FMAE
Frequently Asked Questions
What is FMAE?
The Financial Model Audit Engine, a deterministic, rule-based engine that applies a fixed set of structural rules to an Excel financial model and produces reproducible findings about its structure.
Is FMAE available as standalone software?
No. FMAE is priced to convert clients into one of the nine engagement products built on the engine, and never appears as a standalone revenue line or a peer product in its own right.
What does FMAE actually check?
Structural properties of a model, including circular references, hardcoded values, broken links, formula and logic consistency, and related structural risks, applied systematically rather than sampled.
Does FMAE assess whether a model's assumptions are correct?
No. Assumption reasonableness, valuation, tax, and accounting judgment are explicitly outside the engine's scope and remain a human responsibility in every engagement.
What does deterministic mean in this context?
Identical input produces byte-identical output. The same model, run through the same engine version, produces the same findings every time, which is what makes the output reproducible and defensible.
What is coverage in an FMAE-generated report?
A disclosure, generated by the engine itself, of exactly what was and was not analysed in a given run, so a deliverable never implies broader testing than what was actually performed.
How is FMAE different from a general-purpose AI reviewing a spreadsheet?
FMAE applies a fixed, deterministic rule set rather than a generative model interpreting a spreadsheet freely. See the Deterministic Audit vs Generative AI Review comparison for the full distinction.
Which Oxxon Advisors products use FMAE?
All nine packaged products draw on the same engine output, from the Independent Structural Model Review through the Audit Evidence Model Review, each applying a different scope and deliverable template.
Related Articles
What Is a Financial Model Audit?
A financial model audit is an independent, structured examination of an Excel based financial model to confirm that its mechanics, logic, and outputs are reliable enough to support a decision. It is not a check of whether the assumptions are optimistic or conservative. It is a check of whether the model actually calculates what its author believes it calculates. Every year, lenders extend debt, investment committees approve capital, and boards sign off on transactions using numbers that came out of a spreadsheet nobody outside the immediate deal team has independently verified. A financial model audit exists to close that gap before it becomes expensive.
Deterministic Audit vs Generative AI Review
Not all AI applied to financial model audit works the same way. This page compares two genuinely different approaches: deterministic audit, a fixed, rule based methodology applied consistently to every formula, and generative AI review, a general purpose large language model reading a model and offering commentary. Both use AI in a loose sense. Only one produces the repeatable, explainable, evidence backed output typically required for a material financial decision.
What Is Model Risk?
Model risk is the risk that a decision is wrong not because the underlying business or investment case was flawed, but because the model used to evaluate it was. It is a distinct category of risk from market risk, credit risk, or operational risk, and it applies to any organisation that relies on a financial model, spreadsheet or otherwise, to support a material decision. Most published model risk content addresses statistical and regulatory capital models used inside banks. This page defines model risk specifically as it applies to Excel based financial models, the kind used every day for investment decisions, lending, and transaction evaluation, which is a related but distinct problem from the quantitative model risk literature most search results return.