Building three financial scenarios: conservative, base, optimistic

Quick answer. Modelling three financial scenarios means deriving conservative, base and optimistic versions from a single forecast by flexing only three to five key drivers. Three scenarios are enough in 90% of cases. The most useful figure is the cash gap between the conservative and base versions, which sets your plan B triggers.

A single-path forecast offers false precision. Nobody knows whether next year's revenue will land on the exact figure in the cell. The real question a business owner faces is not "what will my profit be", but "what happens if I'm wrong, and at what point must I react". That is precisely what conservative, base and optimistic modelling answers.

The aim is not to stack assumptions to reassure a banker. It is to turn a static budget into a decision tool: knowing in advance the revenue threshold below which cash gets tight, and the room you have if things go well. At Hayot Expertise, we systematically build these three sets of assumptions whenever a director prepares a fundraise, a hire or an investment.

A financial scenario is a coherent set of assumptions that produces a complete forecast income statement and cash position. Modelling three scenarios means telling three plausible stories about the same company: one where the economy disappoints, one judged most likely, and one where every indicator turns green.

The value lies not in the figures taken in isolation, but in the gaps between the three paths. If your profit swings from a 30,000 euro loss to an 80,000 euro gain depending on the scenario, you immediately know your model is sensitive and a plan B is essential. This mirrors the French legal logic of early-difficulty prevention: under articles L232-2 and R232-2 of the Commercial Code, companies with at least 300 employees or net revenue above 18,000,000 euros must produce a forecast income statement and a forecast financing plan. Small firms are exempt, but the same discipline keeps them from discovering a cash hole too late.

Three concrete uses justify the effort:

• Securing a decision (a hire, a lease, equipment) by checking it holds even in the conservative scenario.
• Negotiating financing by showing the bank you have anticipated a downturn, not only growth.
• Defining a plan B before the crisis, calmly, while judgement is still clear.

Three scenarios are enough in the vast majority of the files we handle. Below three, you lose the sense of range. Above five, the model becomes unreadable and nobody uses it. The practical rule: one scenario per reversible decision you want to secure.

The conservative / base / optimistic trio covers everyday management needs. You can add a fourth "disruption" scenario (loss of a major client, end of a grant) only where that risk is identified and material. Multiplying variants for intellectual comfort is counterproductive: a useful model is one you actually update every month.

The method rests on one discipline: touch only the drivers that matter, and keep an identical structure across the three versions so they can be compared line by line.

1. Lock the base scenario as your reference. Build a documented base forecast first, where every sales, margin and cost assumption is justified. This is your reference column.
2. Identify the key drivers. Find the three to five levers that weigh most: volume, average price, margin rate, customer payment terms, payroll. You will flex only these.
3. Build the conservative version. Degrade each driver realistically (for example revenue down 15%, margin down 2 points, customer terms longer by 15 days), without aiming for the absolute worst.
4. Build the optimistic version. Improve the same drivers with restraint, then check growth remains fundable, because it consumes working capital.
5. Compare the impact on profit and cash. Place the three columns side by side on profit, corporate tax and month-end cash.
6. Set the plan B triggers. Define the thresholds that force action: a cash floor, or a revenue drop beyond a set percentage.

For granular monthly cash, this scenario logic combines well with a 13-week cash flow forecast, which translates each assumption into dated inflows and outflows.

Assumptions make or break a model. A common mistake is to cut revenue while forgetting to adjust variable costs and working capital: the conservative scenario then looks falsely catastrophic, and the optimistic one falsely euphoric.

A few principles we apply on assignment:

• Start from the actuals. Anchor margin rates and payment terms on the last twelve months, not on a target.
• Flex levers, not results. Adjust a price or a volume, never net profit directly.
• Stay coherent. Strong growth usually means more inventory, more staff and higher working capital: the optimistic scenario must reflect it.
• Document every assumption. A one-line note per driver (source of the figure, reason for the choice) makes the model defensible to a banker or investor.

To connect these assumptions to a properly managed annual budget, the approach set out in our article on how to steer your budget throughout the year is complementary, as is the method to build a forecast income statement line by line.

Accounting profit does not kill a business: cash does. That is why the heart of the modelling is the month-end cash gap between scenarios, not profit alone.

The table below illustrates, on a simplified worked example, how three sets of assumptions translate into profit, tax and cash. An eligible French SME is taxed at the reduced corporate-tax rate of 15% on the profit fraction up to 42,500 euros, then at 25% above: the optimistic scenario therefore bears proportionally more tax, which narrows the expected net cash gap.

In this example, the management signal is clear: the conservative scenario pushes cash below the floor as early as month seven. It is this precise point, not the annual loss, that should trigger a credit line or the deferral of an investment. To isolate a single, sharp shock to revenue rather than three permanent paths, a cash-flow stress test on a one-off shock is the suitable complementary tool.

Seasonal activity. Annual reasoning hides the troughs. For a retailer or a tourism business, model the three scenarios monthly, because the cash floor often plays out over two or three specific months, not the yearly average.

High-growth startup. The optimistic scenario is the most dangerous to neglect: rapid growth consumes working capital massively. We support these files with an outsourced CFO for startups and SMEs to link scenarios, runway and the fundraising calendar.

Consultant or independent professional. With few fixed costs, the gap between scenarios comes mainly from billed days and payment terms. The conservative scenario must include a realistic lean period, common in advisory work.

Company preparing financing. The bank wants the conservative scenario to cover the repayment. Presenting only the optimistic case weakens your credibility.

Several mistakes recur in the files we take over.

• Confusing scenario with target. The optimistic scenario is not your sales goal: it is a high assumption, not a commitment.
• Forgetting tax and VAT. A good result generates corporate tax, and collected VAT is not your cash. The optimistic scenario must provision these outflows.
• Neglecting working capital. This is the costliest blind spot: growth funded by customer credit can drain cash despite a profit.
• Never updating. A set of scenarios frozen in January is useless by June. The logic of a rolling forecast over a fixed annual budget keeps the model alive.

In growth files, the danger is not the conservative scenario, already watched. It is the optimistic one. A company doubling its revenue must finance more inventory, more salaries paid before customer receipts, sometimes more equipment. Profit rises on paper, but cash can plunge. Too many directors prepare a plan B for bad news and none for good news. That is the omission we correct most often.

Recently, a director of a services SME asked us to validate hiring three salespeople funded by expected growth. His single-path forecast showed a comfortable result. Building the three scenarios, the conservative version revealed cash falling below the floor by month five if the first contracts slipped by a quarter, a very likely outcome for a new salesperson. We recommended phased hiring and the precautionary opening of a short-term line. Six months later, the commercial slippage did occur, but the company absorbed it without strain.

Our reading is consistent: the value of a three-scenario model lies not in its precision, but in its ability to turn uncertainty into a written decision before the crisis. As chartered accountants registered with the French Ordre, we see too many directors endure decisions they could have framed six months earlier. The right reflex is not to hunt for the "true" figure, but to know your trigger thresholds and write them down.

Hayot Expertise tip. Build a rigorous base scenario first, then derive the conservative and optimistic versions by touching only four or five drivers. Put the cash gap at the centre, not profit. Write down the thresholds that trigger action, and review the model every month. A living model beats a perfect one never opened.

To embed this approach for the long term, we can help you build a solid forecast balance sheet and steer it over time. Directors who want to deepen the cash dimension will find a complete framework in our director's cash management guide.