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.