What-if planning

A scenario planning tool built from assumptions

A practical scenario-planning tool should preserve the baseline, expose the variables that matter, and let you change assumptions without rebuilding the model.

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Live model

Change an assumption.
Read the consequence.

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Editable source

# Runway scenario
starting_cash = 30000 in usd
monthly_costs = 2800 in usd
monthly_income = 600 in usd
net_burn = monthly_costs - monthly_income
baseline_runway = starting_cash / net_burn
lower_costs = monthly_costs - 500 in usd
lean_runway = starting_cash / (lower_costs - monthly_income)
months_bought = lean_runway - baseline_runway

Inputs

What the model needs

Baseline: The current best estimate before optimistic or conservative changes.
Decision variable: The input you can change or influence.
External uncertainty: A rate, delay, cost, or outcome outside direct control.
Threshold: The result at which the planned action changes.
Time horizon: How long the assumptions are expected to matter.

Method

Formulas stay visible

baseline_result = model(current assumptions)downside_result = model(conservative assumptions)upside_result = model(optimistic assumptions)decision changes when a named result crosses the stated threshold

Continuum keeps the authored source canonical. The full production template adds interpretation and a richer preview without hiding these relationships.

Worked example

What does a $500 monthly cut buy?

$30,000 cash
$2,800 costs
$600 income
$500 possible cost reduction

ResultBaseline runway is about 13.6 months; the lean case is about 17.6 months.

The change buys roughly four months. The decision can now be framed as whether the cut is worth four months of additional time.

Stress-test it

Change one important assumption at a time before combining changes.
Keep the baseline visible so a scenario does not quietly become a forecast.
Name the threshold that would cause a different action.

Use it when

A decision depends on several uncertain numbers
You want to explain why a conclusion changed
A spreadsheet feels heavier than the model requires

Know the boundary

A scenario is not a probability unless probabilities are explicitly modeled.
More scenarios do not compensate for weak assumptions.
Continuum keeps the reasoning visible; it does not remove uncertainty.

Questions

What is the difference between a scenario and a forecast?

A forecast is a best estimate of what may happen. A scenario is a coherent set of assumptions used to explore what would happen if those conditions held.

How many scenarios should I create?

Begin with a baseline and one materially different case. Add another only when it represents a distinct uncertainty or action, not a cosmetic variation.

Can scenario planning work without a spreadsheet?

Yes, when the relationships fit a readable model. Large datasets and repeated tabular operations may still belong in a spreadsheet.

Keep the reasoning

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your living model.

The full template opens as a local Continuum document. Edit every assumption, use the production preview, and keep the source.

Open a scenario planning tool built from assumptions

A scenario planning tool built from assumptions

What the model needs

Formulas stay visible

Stress-test it

Use it when

Know the boundary

Turn this example intoyour living model.

Structured thinking with numbers

Cash runway calculator

LTV to CAC calculator

Turn this example into
your living model.