FORMULA CARD

Build downside, base and upside cases

Change a small number of assumptions and state what must be true in each case

Scenario discipline

  1. Start from one accepted base case.
  2. Choose no more than three decision-driving assumptions.
  3. Set downside and upside values with evidence.
  4. Calculate the change in the decision output.
  5. Write the observable condition that would make each case credible.

A good scenario

Downside: volume growth slows to 2% because the disclosed order backlog declines; EBIT margin remains at 12% because fixed costs do not flex.

A weak scenario

“Downside = bad market” without a changed assumption, mechanism or observable evidence.