The idea
A scenario is a coherent account of how a system could develop under stated assumptions. Comparing scenarios can reveal which decisions remain useful across several futures. The exercise is strongest when assumptions, causal links, and observable indicators are explicit.
Worked example
A fictional community garden considers rapid membership growth, steady participation, and a decline after a nearby housing change. For each future it sketches membership, volunteer hours, maintenance needs, and costs over two years. A modular tool shed works across all three futures better than a large fixed expansion. The garden does not assign certainty to any scenario. It identifies which early signals would justify revisiting the choice.
Use it carefully
Scenarios should differ in meaningful mechanisms rather than merely optimistic and pessimistic adjectives. Internal consistency matters: rapid growth with unchanged volunteer demand needs an explanation. Do not attach precise probabilities without a defensible basis, and include outcomes that challenge the preferred strategy. A robust option can still be costly or imperfect; scenario comparison clarifies resilience, not a guarantee against surprises.
FROM UNDERSTANDING TO ACTION
Put it to work.
Create three coherent futures for a local project. Name one observable sign and one decision adjustment for each.
RETRIEVE. REASON. REMEMBER.
Knowledge check.
Choose one answer for each question, then check your reasoning.
Sources & further reading.
Links support the core concepts or identify the book. Examples, exercises, and critical analysis are original Institute material. Source checks are not an independent expert review of every claim.
- MIT System Dynamics: strategy, simulation, and alternative futures ↗
MIT System Dynamics: strategy, simulation, and alternative futures; supports the core concept. Scenarios, calculations, and practice questions are original. Source reviewed 2026-10-19.