Case math framework

Profitability Tree

TL;DR

A profitability tree is a structured decomposition of a company's profit into its underlying drivers: Profit = Revenue minus Costs, then breaking each side until you reach a driver concrete enough to act on. It is the default framework for profitability and cost-out case interviews.

Last updated: May 16, 2026. Written by the CaseXcel team.

When to use Profitability Tree

  • Any case where the prompt is "profits are down" or "improve margins".
  • Cost-out cases.
  • Cases asking why one segment or product line is less profitable than another.

When NOT to use it

  • Industry attractiveness or market entry cases (use Five Forces or 3Cs).
  • Marketing or product launch cases (use 4Ps).

The components

Profit = Revenue − Costs

The trunk of the tree.

Revenue = Price × Quantity

Break by product line, customer segment, geography, or channel — whichever the data supports.

Costs = Fixed + Variable

Then by cost line: COGS, labor, rent, marketing, etc. Quantify which lines grew.

Drivers

Each leaf becomes a driver that is concrete enough to investigate or change.

Worked example

Prompt

A regional restaurant chain's profits are down 25% year over year while revenue is flat. Why?

Walkthrough

  1. Profits down 25%, revenue flat → the issue is on the cost side.
  2. Decompose costs: COGS (food + beverage), labor, rent, utilities, marketing.
  3. COGS up 15% — beef and dairy inflation. Labor up 8% — minimum wage increases in two states. Rent flat. Utilities up 12%. Marketing down (savings).
  4. Cost increases concentrated in COGS and labor, both partially structural (wages) and partially cyclical (inputs).

Recommendation

Two levers: (1) renegotiate beef and dairy supply contracts or substitute some menu items toward chicken and grain-forward dishes; (2) optimize labor scheduling against demand curves, particularly in the two minimum-wage states. Target margin recovery of 8-12 points over 12 months.

Common mistakes

Not segmenting

A flat revenue line can hide one rising segment and one falling segment. Always break revenue by segment if you can.

Listing both sides without prioritizing

If profit is down and revenue is flat, you do not need to investigate revenue. State that, and dig into costs.

Skipping the math

Profitability cases are math cases. Quantify the size of each cost line and the percentage change. Without numbers, your tree is decoration.

Drill Profitability Tree until it is automatic

The CaseXcel app drills framework recall with Leitner-style spaced repetition, so the structure is in your head when the interviewer asks. Plus mental math, case math, and market sizing in the same daily session.

Try a free drill →

FAQ

Is the profitability tree a McKinsey framework?

It is a generic case-math framework used at all major consulting firms. The exact decomposition you draw is yours to build, not a memorized template.

How deep should I take the tree in an interview?

Two to three levels is enough. Past that, you lose the audience. Build to the level where you can ask for data and start computing.

Related frameworks

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