Model Governance During Transactions
Executive Summary
Key Takeaways
- ✓ Transaction model governance faces a specific pressure general model governance practice does not fully anticipate — rapid change across multiple contributing parties against hard external deadlines, with version discipline the first casualty when time pressure is highest.
- ✓ A single, unambiguous source of truth for "the current model version" must be maintained throughout the process, since a deal team working from an outdated version can make decisions based on figures the authoritative model has already superseded.
- ✓ Sign-off authority for changes to a live deal model should be explicitly defined before the process intensifies, not worked out ad hoc once multiple parties are simultaneously requesting or making changes under deadline pressure.
- ✓ Documentation discipline — recording what changed, why, and who approved it — is most valuable exactly when it is most tempting to skip, during the final, highest-pressure stretch before signing.
- ✓ Post-signing model handover to the buyer's ongoing finance function should follow the same documentation and structural discipline as any other model handover, since a deal model that served its transaction purpose well can still be poorly suited for ongoing use if handover discipline is neglected.
Objective¶
This guide extends the existing Model Governance discipline to the specific pressures of a live transaction, within the Financial Model Due Diligence pillar.
Why Transactions Stress General Model Governance Practice¶
| Pressure | Ordinary Operating Model | Live Deal Model |
|---|---|---|
| Rate of change | Periodic, predictable update cycle | Rapid, often multiple revisions per day near signing |
| Number of contributing parties | Typically a single team | Deal team, multiple advisors, sometimes the target's own team |
| Deadline structure | Internal planning calendar | Hard external deadlines (signing, financial close) with real consequences for missing them |
| Consequence of a version error | An internal reporting inconsistency | A price or term negotiated against a superseded figure |
Version Control as the Central Discipline¶
A single, unambiguous source of truth for the currently authoritative model version must be maintained throughout the transaction process. This sounds elementary but is the discipline most frequently broken under deal pressure — a deal team member working from an email attachment sent two revisions ago, or an advisor's local copy that has diverged from the shared version, can each introduce a decision based on figures the authoritative model has already superseded. See the existing Version Control for Financial Models for the general discipline this extends.
Sign-Off Authority¶
Who has authority to change a live deal model — and under what circumstances a change requires review before being incorporated — should be explicitly established before the process intensifies, not negotiated ad hoc once multiple parties are simultaneously requesting or making changes under deadline pressure. Establishing this early specifically protects the highest-risk moment in the model's life: the final, most rapid-change period immediately before signing, which is also, without deliberate governance discipline, the period least likely to have careful review applied to each change.
Documentation Under Time Pressure¶
Recording what changed, why, and who approved it is most valuable exactly when it is most tempting to skip — during the final stretch before signing, when the pressure to move fast is highest. An undocumented, unexplained change made during this period is the change most likely to be relied upon by the deal team without adequate scrutiny, precisely because there is no time to trace its origin or rationale before the deal closes.
Post-Signing Handover¶
A deal model that served its transaction purpose well is not automatically well-suited for the buyer's ongoing operational use — post-signing handover to the acquirer's finance function should follow the same documentation and structural discipline as any other model handover. See the existing Model Handover glossary page for the general discipline this applies.
Structural Checks Specific to Transaction Model Governance¶
| Check | What It Catches |
|---|---|
| A single, clearly labelled authoritative version exists at every point in the process | A decision made against a superseded figure |
| Sign-off authority for model changes is explicitly defined before the process intensifies | Ad hoc, unreviewed changes made under deadline pressure |
| Every change during the final pre-signing period is documented with rationale and approver | An unexplained, unscrutinized change relied upon in the final deal terms |
| Post-signing handover documentation is prepared to the same standard as any other model handover | A deal model that is structurally sound for transaction purposes but unusable for ongoing operational reporting |
Continue Reading¶
Prerequisites¶
- Financial Model Due Diligence — the parent pillar
- Model Governance
Related Technical Guides¶
Related Glossary¶
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Frequently Asked Questions
Why does model governance need specific treatment in a transaction context?
Because a deal model typically changes rapidly, across multiple contributing parties, against hard external deadlines — a combination of pressures that general model governance practice, built around an ongoing operating model's steadier change cadence, does not fully anticipate.
What is the single most important model governance discipline during a live deal?
Maintaining a single, unambiguous source of truth for which version is currently authoritative — a deal team working from an outdated version can make pricing or structuring decisions based on figures the authoritative model has already superseded, a risk that compounds as deadline pressure increases.
When should sign-off authority for model changes be established?
Before the process intensifies, not worked out ad hoc once multiple parties are simultaneously requesting or making changes under deadline pressure — establishing this early avoids exactly the highest-risk moment (last-minute changes under time pressure) being also the moment with the least governance discipline in place.
Why is documentation discipline hardest to maintain exactly when it matters most?
Because the final stretch before signing is typically the highest-pressure, most rapid-change period in the model's life, and documentation is the first discipline sacrificed under deadline pressure — precisely the period in which an undocumented, unexplained change is most likely to be relied upon without adequate scrutiny.
Does model governance discipline matter after signing?
Yes — post-signing model handover to the buyer's ongoing finance function should follow the same documentation and structural discipline as any other model handover, since a deal model built well enough to serve its transaction purpose can still be poorly suited for ongoing operational use if handover discipline is neglected.
Related Articles
Financial Model Due Diligence
Financial model due diligence is the discipline of testing whether the financial model used to price, structure, or finance a transaction is itself structurally sound — a distinct question from whether the target business's historical financials are reliable (the domain of financial due diligence) or whether its commercial prospects are durable (commercial due diligence). A model can be structurally unsound — an untraceable synergy figure, a broken purchase price allocation link, a hardcoded override masking the true output of a formula — independent of whether the underlying business is fundamentally healthy, and this risk is what financial model due diligence is specifically built to catch. This page is the hub for the Knowledge Centre's model-risk-in-transactions content: how model review differs by audience (independent, lender, investor, vendor), how it differs from a quality of earnings review, and how transaction-specific model risk maps onto FMAE's own structural rule set.
Model Governance
Model governance is the organisational framework through which an institution defines, implements, and enforces policies and controls for the development, approval, use, validation, change, and retirement of financial models. It establishes accountability for model quality, a structured process for model oversight, and a documented record of model use and validation history. Effective model governance ensures that decisions made using financial models are based on outputs that have been developed to an appropriate standard, validated by a party independent of the developer, and used within the bounds for which they were designed.
Model Risk During Transactions
Model risk during a transaction concentrates in mechanics that do not exist in either party's ordinary-course, standalone model — purchase price allocation, financing structure, pro-forma consolidation, and synergy assumptions — each a new potential point of structural failure introduced specifically by the transaction itself. This guide maps where that risk concentrates and why it is structurally independent of whether the underlying business being acquired is fundamentally sound.
Version Control for Financial Models
Version control for financial models is the systematic management of changes to a model over time, ensuring that each version of the model is identifiable, that all material changes are recorded with their date and author, and that previous versions can be recovered when needed. Unlike software version control systems (such as Git), financial model version control is typically implemented through a combination of file naming conventions, an in-model change log, and an archive of previous model files. The FAST Standard and the ICAEW Financial Modelling Code both require a version control protocol as a core component of institutional model governance.
Model Handover
Model handover is the structured process by which responsibility for a financial model — including operational ownership, update obligations, and decision-making authority — is formally transferred from one individual or team to another. It encompasses the transfer of the model file, all associated documentation, version history, and the knowledge required to operate the model correctly and safely. Model handover occurs in several contexts: when a staff member leaves an organisation, when a project transitions from development to operations, when an advisory firm concludes an engagement and returns a model to the client, or when model ownership is reassigned within a team.