Glossary

Sensitivity Analysis

The practice of varying a model's key assumptions to see how much the answer moves. The difference between a forecast that informs a decision and a single number that merely decorates one.

Any business case can be made to clear a hurdle. Sensitivity analysis reveals how hard the authors had to try, which is often the most decision-relevant fact in the whole pack.

Last reviewed 3 July 2026 · Free and ungated

Challenge the assumptions before committing

Which of your break-even assumptions have failed elsewhere? The Global Board can tell you, confidentially, before sign-off.

Challenge the assumptions before committing

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What the exercise involves

Sensitivity analysis takes a financial or operational model and systematically varies its inputs, adoption rates, prices, volumes, timelines, discount rates, to show how the output responds. Its products are simple: which assumptions the result is most sensitive to, and how far each can move before the recommendation changes.

The difference between a forecast and an argument

A case presented as one scenario is an argument; sensitivity turns it back into a forecast by exposing its load-bearing walls. For the person who must approve the commitment, two outputs matter most. The first is the break-even point of each major assumption, the adoption rate or price at which the case stops working, because that can be compared against lived experience. The second is which variables the outcome barely responds to, since arguments in the room have a habit of concentrating on visible assumptions rather than consequential ones. Knowing the difference redirects scarce challenge to where it changes the decision.

How the analysis gets defanged

  • Ranges of plus or minus five per cent applied to assumptions that history says move by fifty.
  • Variables flexed one at a time, hiding the correlated failure where delay, cost and adoption slip together.
  • Sensitivities run on the harmless inputs while the terminal assumption is held fixed.
  • The analysis performed after approval, as documentation rather than as preparation.

Find the assumption the whole case is standing on.

Challenge the assumptions before committing