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.

Open the full model Try it on this page

Live model

Change an assumption.
Read the consequence.

Enter your assumptions to see an estimate. Use source view to inspect or change the calculation. Your inputs stay in this browser.

Worked exampleCalculate in your browser

Assumptions

template: runway

savings = 30000 in usd
monthly_burn = 2800 in usd
monthly_income = 600 in usd
burn_change_rate = 3%

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

The inputs and source use the same model. Open it in Continuum for a document you can keep and revisit.

Worked example

What does a $500 monthly cut buy?

$30,000 cash
$2,800 costs
$600 income
$500 possible cost reduction
3% annual expense growth

ResultWith 3% annual expense growth, baseline runway is about 13.37 months; reducing monthly costs to $2,300 gives about 17.18 months.

The change buys about 3.8 months under the same growth assumption. Set burn change to zero to compare the flat-expense estimates of 13.64 and 17.65 months.

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

Turn this example into
your living model.

The full template opens as a local Continuum document. Edit every assumption, explore the result breakdown, 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.