Profitability framework

If you memorize a single structure, make it this one, because profitability is the most common case type and the profit tree is embedded inside market-entry, pricing, and M&A cases too. Start from the identity and disaggregate:

Profit = Revenue − Cost
   Revenue = Volume × Price
      Volume = market size × market share              (or: # customers × units per customer)
               → by segment: Σ (Qᵢ × Pᵢ)               (mix lives here)
      Price   = list price − discounts/returns          (net realization)
   Cost = Variable + Fixed
      Variable = per-unit cost × Volume                 (COGS, materials, delivery)
      Fixed    = rent + salaries + overhead + D&A       (does not move with Volume)

Two derived quantities do most of the work:

• Contribution margin per unit = Price − Variable cost per unit. It is the money each sale contributes toward fixed costs and profit. A profitability case is very often a story about contribution margin per unit falling (input costs rose faster than price) or volume falling (so total contribution can no longer cover fixed cost).
• Breakeven volume = Fixed cost ÷ Contribution margin per unit. The number of units that exactly covers fixed cost. Everything sold beyond breakeven is profit; everything short of it is loss. Breakeven turns a vague "are we viable?" into a crisp, checkable number.

How do you explain a change in profit?

The profit bridge, the technique that separates good candidates from great ones. When a profit changed between two periods, do not just say "revenue fell and costs rose." Decompose the change into named effects that sum exactly to the total change:

Δ Profit = Δ Contribution − Δ Fixed cost
Δ Contribution (per segment) can be split into:
   Volume effect = Δ Volume × old contribution-per-unit
   Margin effect = new Volume × Δ contribution-per-unit

A bridge that reconciles to the penny is the difference between "profits are down because things got worse" (a novice) and "of the ₹40 crore drop, all of it is in the milk line, where procurement rose ₹5/litre while price rose only ₹2 — the value-added line actually grew" (a consultant). Worked example 3 does exactly this. The bridge tells you not just that profit fell but exactly where the leak is, which is the whole point of the engagement.

A profit-tree checklist to run in your head: Is the problem revenue or cost (or both)? If revenue: is it volume or price? If volume: is it market shrinking (external) or share loss (us)? If cost: variable (per-unit economics) or fixed (overhead/utilization)? Is there a mix story hiding under the aggregate (a segment cut)?

Answering those five branches, in order, cracks the large majority of profitability cases.