Case Interview Examples: Worked Mini-Cases You Can Steal the Moves From

This page is a set of short, fully worked examples so you can see the moves: clarify, tree, math, so-what, close. It is not a 40-link dump pretending to be a case library, and it is not the prep guide. For type definitions, use case types. For question-by-stage patterns, use questions.

CoachNed’s live library is 63 voice-ready cases (first full case free). Official firm PDFs and MBA casebooks are listed at the end as prompts, not as answer keys to memorize.

Example 1 — Profitability: a foundry’s overtime

Prompt. A mid-size foundry’s EBIT fell from $14m to $9m. Volume is up 6%. They want to know why and what to do.

Clarify. Time horizon last FY vs prior. Success: restore EBIT, not share. Cannot close the union shop in this case.

Tree. Price, mix, volume, variable cost (scrap, energy), overtime / shift premium, overhead.

Math. Volume +6% should have helped. Suppose contribution per ton was $220 on 80k tons = $17.6m, fixed $8m, EBIT $9.6m last year (numbers rounded to the story). This year: tons 84.8k, but scrap rose 2pp and energy +$18/ton. Extra scrap+energy ≈ 84.8k × ($18 + scrap $12) ≈ $2.5m. Overtime premiums +$1.8m. Price down $4/ton ≈ $0.34m. Bridge lands near a $5m EBIT hit. So-what: this is a cost/yield problem with a small price leak, not a demand problem.

Close. Do not run a volume promo. Kill overtime on the two cells with scrap above 5%; energy hedge is a finance workstream, not the case rec. Risk: yield project slips. Next: 4-week scrap dashboard by cell.

Example 2 — Entry: charging depots for vans

Prompt. Should a fuel retailer put EV charging for delivery vans on 40 highway sites?

Clarify. Organic build vs partner. Metric: 3-year NPV vs year-1 cash. Grid upgrades allowed.

Tree. Van traffic that actually dwells 30+ minutes, utilization, power cost and connection fees, competitive chargers, capex per site.

Math. 40 sites × 8 stalls. If realistic utilization is 18% at $0.42/kWh gross and $0.28 power+fees, contribution per stall-year is thin. 40 × 8 × 0.18 × 4,000 hours × 50 kW × $0.14 ≈ $1.6m/year before capex. If capex is $2.2m/site, 40 sites = $88m. So-what: utilization would need to look like a depot contract, not retail passing traffic.

Close. Do not build 40 retail sites. Pilot 3 sites next to existing fleet customers with take-or-pay. Risk: OEM-owned depots. Next: two fleet RFPs before any highway capex.

Example 3 — Pricing: industrial adhesives list vs discount

Prompt. Sales wants a 7% list cut to stop share loss.

Clarify. Contribution, not revenue. Contracts reset in 90 days. Competitor already 5% below.

Tree. Elasticity by segment, discount leakage, cost-to-serve, competitive reaction.

Math. Price $4.00, variable $2.40, contribution $1.60. 7% list cut → $3.72, contribution $1.32 if discounts still stack. Need volume +21% just to break even on contribution (1.60/1.32 − 1). If sales can only show +8% in the last war, the cut destroys contribution.

Close. No blanket list cut. Segment: match on the 15% of volume that is tender-driven; hold list on spec-in products. Risk: sales ignores the fence. Next: 90-day deal desk with a contribution floor.

Example 4 — Operations: airport security lanes

Prompt. Wait times at security doubled. Board wants a rec in two weeks.

Clarify. Metric: 95th percentile wait, not average. Cannot add a terminal.

Tree. Demand peaks, lane throughput, staffing, equipment downtime, passenger mix (PreCheck vs not).

Math. If each lane does 180 pax/hour and peak is 1,100 in 45 minutes, you need ~8 lanes in the peak slice, they have 6. Two lanes of overtime staffing is cheaper than a new machine if downtime is 4%. So-what: this is a peak-staffing problem unless downtime exhibit says otherwise.

Close. Staff to the peak with a cross-trained pool; publish a 95th-percentile dashboard. Risk: union rules on shift starts. Next: one week of timestamped queue data.

How to use these without memorizing industries

Steal the move, not the sector. Each example has a clarify that changed the tree, math that could flip the rec, and a close with a number. If your practice cases lack those three, they are stories, not cases.

Videos of other people casing: video examples. Your own reps: how to practice.

Official practice cases (prompts, not CoachNed content)

Firms publish sample cases that change URLs. Search the careers site for the current PDF. Typical names: McKinsey practice cases, BCG interactive cases, Bain case interview, Deloitte case studies. MBA clubs (Wharton, Ross, Darden, etc.) publish casebooks — use as prompts, check the math, ignore dated frameworks.

Free index of tools: free resources.

Next step

Work one mini-example out loud from a blank page, then sit a full scored case in the same family.

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CoachNed is independent and unaffiliated with McKinsey, BCG, Bain, Deloitte, or other firms. Cases on CoachNed are AI-simulated.