Scenario Planning: Change the Assumption, Not Every Cell

Best case, base case and worst case are easy labels to add to a workbook. They are harder to use when nobody can explain which real-world assumptions separate them.

A useful scenario changes a specific event: a contract starts later, a customer pays slowly, a supplier requires a deposit or a hire begins earlier. The financial effects follow from that event.

A scenario is a story with linked numbers. It is not the same percentage adjustment applied to every line.

Begin with a base you can explain

Document the current operating plan, its cut-off date and the evidence behind material assumptions. Separate invoiced receipts, signed work and unsigned pipeline. State how uncertain amounts are treated before introducing alternatives.

Keep the base stable while comparing scenarios. Otherwise, a changed starting point can be mistaken for the effect of the decision you are testing.

For the cash mechanics, the Xero cash forecast template guide describes placing upcoming income and costs on a timeline. The following example applies that structure to three deliberately simple scenarios.

Compare a delay with a genuine loss

Illustrative example. A business opens month one with A$80,000. The base case has collections of A$90,000, A$70,000 and A$100,000 over three months, against payments of A$110,000, A$80,000 and A$80,000. All figures below are A$000 cash amounts, assumed to include any applicable tax movements.

In the delayed-payment case, A$30,000 of month-one collections moves to month two. Total receipts do not change. In the lost-contract case, A$30,000 of month-one receipts never arrives, but A$10,000 of related month-one delivery payments is avoided. All other assumptions stay the same.

Illustrative closing cash by scenario — A$000

Scenario	Month 1	Month 2	Month 3
Base plan	60	50	70
30 of receipts delayed one month	30	50	70
30 lost receipts; 10 delivery cost avoided	40	30	50

The delayed-payment case returns to the base balance in month two. The lost-contract case remains A$20,000 below it because the lost receipt exceeds the avoided payment by that amount.

Suppose the team has chosen an illustrative A$35,000 operating buffer. Both alternatives fall A$5,000 below it at a month-end, but in different months. The same buffer breach does not mean the underlying problem is the same.

These are month-end balances, not the lowest daily balances. Before making a payment decision, examine the actual weeks and days inside any tight month.

Keep linked effects together

A delayed payment can reduce cash and increase receivables without changing earned revenue. A cancelled future contract can change revenue, delivery activity and costs. A hiring decision can change recurring payments and capacity before it changes customer collections.

Move the driver once and trace its consequences through the schedules. Avoid manually editing the revenue total, a cash total and a balance-sheet figure to create an apparently consistent result.

The three-way forecasting guide shows the accounting links. The pipeline guide explains why a win probability is not a promise that part of a contract will be paid.

Attach a decision to each scenario

For each alternative, record the trigger, the person watching it and the action that becomes relevant. A trigger might be a customer missing a confirmed payment date or a contract remaining unsigned by the intended delivery start.

Possible management actions should be achievable and authorised: confirm customer timing, review discretionary spending or reconsider the start date of a planned project. Do not treat legally required payments or unapproved finance as flexible assumptions.

Model the action separately from the problem. For example, show the cash effect of a delayed customer receipt first, then the effect of moving a discretionary purchase. That makes the proposed response visible rather than hiding it inside a convenient downside.

Do not average away a commitment

A probability-weighted expected value can support planning, but it may not describe any outcome the bank will experience. A large uncertain receipt deserves a distinct no-receipt case before the business relies on it to fund fixed payments.

Use probabilities only where they have a defensible basis, and label the uncertainty. More decimal places do not make a sales assumption more reliable.

Bring the scenarios back to the operating meeting

Review the few drivers that could change the next decision. Archive alternatives that are no longer plausible and retain the version used to approve a commitment.

Pair the strategic scenarios with a 13-week cash forecast. Explore MagicHub for our approach to connecting operational decisions with their financial consequences.

General business education only, not accounting, tax, legal or financial advice. Worked examples are fictional and simplified, not customer results or industry benchmarks. Confirm the assumptions and obligations that apply to your business with your adviser.