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FP&A / PREPARATION DESK

Driver-Based Forecasting: FP&A Interview Practice

Translate customer, capacity and pricing assumptions into a forecast that an operating manager can challenge and update.

Wall Street Playbook Editorial · September 24, 2026 · Original practice material

A driver forecast makes the reason for a financial result visible. Instead of entering a growth percentage and moving on, connect revenue and costs to the activity that produces them. The right drivers depend on the business and the decision.

Choose drivers the business can observe

BusinessPossible revenue driversImportant limitation
ServicesStaff, hours, utilization, realized rateCapacity and demand must agree
SubscriptionCustomers, churn, expansion, priceBookings and recognized revenue differ
DistributionUnits, mix, discountsInventory and supplier terms affect cash

A driver is not useful just because it correlates with revenue. Ask whether its definition is stable, whether the business can provide it and whether changing it leads to a meaningful operating discussion.

An original forecast exercise

A fictional service firm has 22 consultants, 160 available hours per month, 68% utilization and a $150 realized rate. Loaded monthly compensation is $10,000 per consultant and other costs are $80,000.

Revenue is 22 × 160 × 68% × $150 = $359,040. Payroll is $220,000, so operating profit is $59,040. If utilization falls to 60%, revenue is $316,800 and profit is $16,800. The eight-point utilization change removes $42,240 of profit under the fixed-cost assumptions.

The forecast should identify which signed projects support 68% utilization and what hiring or delivery constraints could change it. A sales pipeline by itself does not establish staffed, billable work in the modeled month.

Separate base, target and upside

The target states the desired result. The base forecast reflects the current evidence. An upside case shows what would happen if additional opportunities convert. Preserve the distinction so management can see the action needed to close the gap.

For each major input, record an owner, evidence, update date and trigger. A driver forecast without an update process becomes a static spreadsheet with more formulas.

Present a recommendation

Explain which driver matters most and the decision it affects. In this case, staffing should be considered alongside signed demand, recruitment lead time and sustainable utilization. More staff can increase sales while reducing short-term profit if capacity arrives before work.

Use the modeling test guide to structure the spreadsheet. The FP&A workbook adds headcount timing, cash and investment cases. For practitioner context on aligning planning with operations, see AFP's driver-model case article; its company example is separate from the fictional exercise here.

Continue your preparation.

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