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FP&A Case Study Interview: A Worked Margin Case

Practice a reconciled profit bridge, explain what caused the miss and turn the analysis into a management decision.

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

An FP&A case study asks you to make a useful decision from financial and operating information. The format varies by employer: a timed spreadsheet, a take-home exercise or a live discussion. Clarify the requested output and available time before deciding how much model to build.

Start with the comparison

Identify the period, currency, units and comparison version. Actual versus original budget answers a different question from actual versus last month's forecast. Reconcile the supplied data first, then separate operational assumptions from calculations.

For a short case, a clean input section, calculation schedule and one-page recommendation are enough to make your reasoning inspectable. Add complexity only when it changes the answer.

Try this original case

Fictional Larch Supply budgeted 10,000 units at a $50 selling price and $30 variable cost. Fixed costs were $120,000. Actual results were 11,000 units at $48, variable cost of $32 and fixed costs of $125,000. Costs are positive amounts subtracted from revenue.

MetricBudgetActual
Revenue$500,000$528,000
Contribution$200,000$176,000
Operating profit$80,000$51,000

Revenue is $28,000 above plan, but profit is $29,000 below. Explain the difference before proposing an action.

Reconcile the answer

Measure volume at budget contribution per unit: 1,000 additional units × $20 = $20,000 favorable. Measure price and variable-cost changes on actual units: the $2 price reduction costs $22,000, and the $2 cost increase costs another $22,000. Higher fixed costs remove $5,000. The bridge totals negative $29,000.

This convention assigns price/volume interaction to the price term. Other conventions can work if stated consistently. A bridge that does not reconcile should not appear in your presentation.

Explain what management should do next

Do not assume lower price means poor sales execution. Discounts, customer mix, rebates and timing can all affect realized price. Ask for customer-level price changes and a unit-cost split between purchase price, freight and usage. Identify who owns the investigation and whether the issue changes next month's forecast.

Practice a 60-second recommendation, then a three-minute walkthrough. The short version should state the miss, the two largest causes and the decision needed. The longer version should show the assumptions and a downside.

What to practice next

The FP&A workbook contains this full lesson plus staffing, cash and investment cases with answers. Start with its actual PDF sample. For the spreadsheet component, use the FP&A modeling test guide. For application positioning, see the existing FP&A resume guide.

AFP discusses case interviews as a way to explore candidate reasoning; it does not prescribe one universal format. Read the AFP article.

Continue your preparation.

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