Across Scenarios

Test whether the destination still makes sense under plausible alternative futures.

The mortgage math works beautifully, in exactly one world: the one where both incomes continue, insurance stays flat, and nothing breaks. You've stress-tested nothing. The plan isn't wrong; it's untested against the futures that have a real chance of showing up, which is a different kind of wrong.

Across Scenarios tests whether a destination remains acceptable under plausible alternative futures, before you commit. The cue: a plan justified entirely inside its expected case, or the phrase "assuming everything goes normally" doing heavy lifting. Run it in three steps. First, ask the move question: which changed assumption would make this target harmful, impossible, or irrelevant? Second, pick two or three plausible variants, for the mortgage, the spec's set is normal income, a six-month job loss, and higher insurance costs, and walk the plan through each. Third, respond to what breaks: shrink the loan, grow the reserve, or accept the risk knowingly and in writing. What changes when it works: the plan either survives the test or gets modified while modification is still cheap, and "we knew this could happen" replaces panic. The boundary that keeps this fast: don't enumerate remote scenarios that couldn't change the decision; a scenario earns its place only by being both plausible and decision-relevant.