Intuition
Profitability cases are the bread and butter of consulting interviews, and they're the most learnable because they're the most structured. "Profits are down — why, and what do we do?" Every one of them yields to the same opening move: profit is revenue minus costs, so figure out which side broke. It's diagnosis before treatment, the way a doctor isolates the symptom before prescribing.
The candidates who struggle are the ones who jump to solutions ("cut costs!") before diagnosing. The ones who shine walk the tree calmly until the single driver pops out.
Framework
- Start with the profit equation. Profit = Revenue − Costs. Establish whether profit fell from the revenue side, the cost side, or both.
- Drill the broken side. Revenue = Price × Volume (then segment by product, region, channel, customer). Costs = Fixed + Variable (then find the line item that moved).
- Quantify and isolate. Use the data to pin the change to one branch — "the entire drop is variable cost, specifically shipping."
- Then prescribe. Only after the driver is isolated do you recommend — and tie the fix to the diagnosed cause.
Worked Example
A meal-kit company's profit fell 20% on flat revenue. Revenue flat → it's a cost problem. Split costs: fixed (kitchens, salaries) is steady; variable costs rose. Within variable, ingredient cost per box jumped after a supplier change. Diagnosis: a procurement problem, not a demand problem. Recommendation: renegotiate or re-source the contract, hedge key inputs, and check whether the prior supplier's quality justified the lower price. Notice the answer came from the tree — you didn't guess "cut costs" up front.
Pitfalls
- Jumping to recommendations before isolating the driver.
- Stopping at "it's a cost problem" without finding the specific line item.
- Forgetting to segment revenue — the drop is often hidden in one region or product while the total looks mild.