A case interviewer hands over a business problem with no obvious entry point. Candidates freeze less often over the math and more often over where to even begin.

Case problems fall into a handful of recurring types, and each type has a structure built for it. A candidate who has memorized frameworks but never practiced recognizing which one applies still freezes when the case starts. Recognition comes first. The framework only works once you know which one to reach for.

MECE — The Structuring Principle Behind Every Framework

Every framework below rests on the same underlying principle: MECE, short for Mutually Exclusive, Collectively Exhaustive. Mutually exclusive means the categories in a structure do not overlap. Collectively exhaustive means they cover the full problem with nothing left out.

In practice, this shows up as the difference between a structure that sounds organized and one that actually is. A candidate who splits a profitability problem into "marketing issues" and "sales issues" has created overlapping, incomplete buckets. A candidate who splits it into price, volume, fixed cost, and variable cost has covered the full problem with no gaps and no overlap. Every framework below applies this same discipline to a specific problem type.

Profitability Framework

Profitability cases ask why a company's profit has dropped or fallen short of target, and the structure starts by splitting profit into its two components: revenue and cost.

On the revenue side, the drop traces back to either price or volume, or some combination of both. On the cost side, it traces back to fixed costs or variable costs. A well-run profitability case moves through each branch systematically, using targeted questions to isolate which side of the equation is actually responsible before jumping to a recommendation. Candidates who skip straight to an answer, like assuming it must be a marketing problem, usually miss a cost-side issue sitting one layer deeper.

Market Entry Framework

Market entry cases ask whether a company should enter a new market or launch a new product, and they call for a different structure entirely. Four dimensions matter here: market attractiveness (size, growth, competitive intensity), the company's ability to compete in that market, entry mode (build, acquire, or partner), and financial viability.

The sequencing matters. A market can look attractive on size alone and still be a poor fit if the company has no real capability to compete in it, so capability has to be checked before financial projections are worth building at all.

M&A Framework

M&A cases ask whether an acquisition makes sense, and the structure centers on where the value actually comes from. Synergies split into revenue synergies (cross-selling, new market access) and cost synergies (economies of scale, eliminated redundancies). Beyond synergies, integration risk and valuation reasonableness round out the picture. A deal with strong theoretical synergies can still fail if the two organizations cannot realistically integrate, or if the price paid already assumes synergies that have not materialized yet.

Pricing Framework

Pricing cases ask how a company should price a product or service, and three approaches typically apply: cost-plus pricing (a markup over cost), value-based pricing (based on what the customer is willing to pay), and competitive pricing (based on what similar products charge). Which approach fits depends on the product. A commodity leans toward competitive pricing, while a differentiated product with real switching costs can support value-based pricing at a premium.

Price sensitivity is the other half of the picture. A single company-wide price often hides the real answer, because business customers and individual consumers frequently respond to the same price change in opposite directions. Segment-level assumptions surface that split. One LSE student who moved from a non-business background into MBB offers built exactly this kind of segment-level thinking under live case conditions.

How Much Practice These Frameworks Actually Take

Reaching for the right framework under a running clock, with an interviewer watching, takes more than knowing it on paper. That comes from running the framework against real cases, repeatedly, until the recognition step stops taking conscious effort. How many cases that repetition typically requires, and what the real offer-rate numbers look like, is covered in more depth in how many cases it actually takes to build case-interview muscle memory. The mechanics of structuring that practice, from mock interview frequency to finding the right practice partner, is its own separate topic worth reading before scheduling a first mock.

One Strategy Group builds its case interview coaching around these frameworks directly, working through each one against live cases rather than teaching them as abstract theory. Students working with One Strategy Group typically drill the framework that matches their weakest case type first, since a case interviewer rarely gives advance notice of which type is coming next.