Advanced Finance

Sensitivity and Scenario Tables

Stop presenting one number. Learn to show which assumption the answer actually depends on, and where the answer flips.

  • Intermediate
  • 7 min total
  • 12 chapters

What decision this helps you make: Which of your model's inputs deserve scrutiny, how wrong each one can be before the decision changes, and what to put in front of an investment committee.

What this topic is

Sensitivity analysis moves one input at a time and records how far the answer travels. Scenario analysis moves a coherent set of inputs together, because in the real world assumptions are correlated. The first tells you where your model is fragile; the second tells you what happens in a particular future.

Why it matters

A single-point answer is a claim of precision no forecast can support. Sensitivity and scenario work converts a fragile number into a defensible range, identifies the two or three assumptions that actually drive the outcome, and — most valuable of all — locates the threshold at which the decision reverses. That threshold is what a committee is really asking for.

Who should learn it

Anyone who builds or reviews financial models: analysts running deal returns, operators budgeting under uncertainty, and decision-makers who need to know which line of a model to interrogate.

What you will understand

  • Sensitivity versus scenario versus stress test — three different questions, three different tools
  • One-way and two-way data tables, and the mechanics that break them
  • How to rank drivers by the swing they cause, and why equal percentage moves are the wrong yardstick
  • Inverting the question: solving for the assumption at which the decision changes

Prerequisites

Common misconception

"We ran a downside case — we cut revenue growth by 300 basis points." That is a sensitivity wearing a scenario's name. In an actual downturn revenue falls, price discipline erodes, working capital builds, capex cannot be cut as fast as sales fall, and the exit multiple compresses. Moving one input while the rest sit at base case describes a world that has never occurred.