Beyond the DCF: Building Financial Models That Executives Actually Trust

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Kyle Garbs

Finance & Management

February 28, 2025

6 min read

A financial model is only as good as the assumptions behind it — and the confidence of the people using it. Here's how to build models that drive decisions, not just back-fill them.

The DCF model is a cornerstone of corporate finance for good reason. It forces rigor around the relationship between cash flows, time, and risk. But if you've ever watched a leadership team dismiss a carefully constructed valuation because "the assumptions feel too optimistic," you know the model's limitation isn't mathematical — it's behavioral.

Executives don't distrust models. They distrust models they don't understand, can't interrogate, and can't connect to the business reality they operate in every day.

The Assumption Problem

Most financial models fail leadership trust tests at the assumption layer. Not because the assumptions are wrong, but because they're buried. When a revenue growth rate of 18% lives in cell C47 of a tab labeled "Inputs," the executive reviewing the output has no intuitive feel for where that number came from or what happens if it's wrong by five points.

The most trusted models I've built and reviewed share a common structural characteristic: the assumptions are front-loaded, labeled in plain English, and visually connected to their downstream effects. Before any executive sees a projection, they should be able to answer three questions by reading the model itself: What are we assuming? Why? And what does a 10% miss look like?

The Scenario Architecture

Single-path models — even sophisticated ones — invite anchor bias. When you present one number, that number becomes the reference point for all subsequent discussion, even when the honest range of outcomes spans 40 percentage points.

Scenario architecture doesn't mean building three different models. It means building one model with a clean scenario toggle, where Base/Downside/Upside are defined by meaningful business narratives, not arbitrary percentage adjustments. "Downside" should mean something specific: what does the world look like if our largest customer churns, or if the product launch slips a quarter? That specificity is what makes the model usable for actual decision-making.

Bridging to Operating Reality

The most common disconnect I see between finance teams and operating leadership is unit economics. A P&L model that produces EBITDA margins in aggregate tells operators almost nothing actionable. The models that earn trust translate financial outputs into the metrics operators recognize: cost per unit produced, revenue per sales rep, gross margin by product line, customer acquisition cost versus lifetime value.

When the finance model speaks the same language as the operating review, the conversation shifts from "I don't believe these numbers" to "here's what we need to change to hit this target."

Model Governance

A model that executives trust in Q1 and distrust in Q3 is a model with a governance problem. Version control, assumption documentation, and regular refresh cycles aren't administrative overhead — they're the infrastructure that keeps a model's credibility intact through organizational change and market shifts.

The organizations that use financial models most effectively treat them as living documents with defined owners, update schedules, and assumption audit trails. When a new CFO asks "where did this WACC assumption come from?" the answer should be one click away, not a search through email archives.

The Build Philosophy

Three principles that guide how we approach financial model development for clients:

  • Transparency over elegance. A model that non-finance executives can navigate is more valuable than one that impresses other analysts.
  • Scenario by design, not afterthought. Build the scenario architecture in before you build the model, not after.
  • Connect to the operating levers. Every financial output should trace back to something an operator can actually pull.

If your current financial models are producing outputs that leadership reviews but doesn't act on, the problem is almost certainly structural. We'd be glad to walk through a model diagnostic — it's usually a shorter conversation than people expect.

FinanceFinancial ModelingStrategyDCFExecutive Communication
K

Kyle Garbs

Finance & Management

Kyle is a finance and management consultant and co-founder of Garbs & Co., specializing in financial modeling, capital strategy, and operational transformation.