Below is a free library of 15 original practice case prompts, sorted by industry and difficulty (Foundation, Intermediate, Advanced), each with key data and a note on what a strong answer covers. All cases are fictional and written for caize.ai. All figures are illustrative, not real company data. Use them with a practice partner or run them as AI-led cases.
How should you use this library?
- Foundation: one clear question, simple maths, good for weeks 1–2.
- Intermediate: multiple steps, an exhibit-style dataset, judgement required.
- Advanced: ambiguous objective, several analyses and a nuanced recommendation.
For each case, the "interviewer" should reveal data only when asked. To run the case with an AI interviewer instead, practise on caize.ai.
Retail and consumer
Case 1: Foundation — Bakery chain profit decline
Prompt: A 40-shop UK bakery chain's annual profit fell from £4m to £2.5m. Why, and what should it do?
Data (reveal on request): Revenue flat at £40m. Ingredient costs up from 25% to 29% of revenue. Staff costs flat. Rent flat.
Strong answer covers: isolating the £1.6m ingredient cost increase as the main driver; options such as pricing, product mix and procurement; quantifying a 4% price rise to offset it.
Case 2: Intermediate — Fashion retailer online returns
Prompt: An online fashion retailer's return rate has risen to 35% of orders. Should it introduce a returns fee?
Data: 2m orders a year, average order £60, cost per return £8 including handling, 40% of returners reorder.
Strong answer covers: current return cost (700k returns × £8 = £5.6m); demand elasticity risk; segmenting by customer type; alternatives such as better sizing tools.
Case 3: Advanced — Grocery checkout-free stores
Prompt: A supermarket is considering rolling out checkout-free technology across 300 convenience stores. Recommend a decision.
Strong answer covers: labour savings versus capex and maintenance; shrinkage risk; customer adoption by segment; a pilot design with clear success metrics.
Healthcare
Case 4: Foundation — Clinic waiting times
Prompt: A private physiotherapy clinic's average waiting time rose from 5 to 12 days. Why?
Data: Demand up 10%; one of six physiotherapists left; appointment length unchanged.
Strong answer covers: a capacity drop of about 17% combined with demand up 10%; hiring and scheduling options.
Case 5: Intermediate — Market sizing for a diagnostic test
Prompt: Estimate the annual UK market for a new at-home test for a chronic condition.
Strong answer covers: patient-based sizing (prevalence × diagnosed × eligible × tests per year × price), explicit assumptions, and how reimbursement affects adoption.
Case 6: Advanced — Hospital group diversification
Prompt: A regional private hospital group is considering entering the outpatient diagnostics market. Should it?
Strong answer covers: market attractiveness, referral flows, capital intensity, staffing constraints and competitive response from NHS and private providers.
Energy and industrials
Case 7: Foundation — Factory output
Prompt: A packaging factory's output fell 15% while staffing was unchanged. Why?
Data: Machine downtime up from 5% to 18% after maintenance contract changes.
Strong answer covers: the downtime root cause; maintenance options; the cost of downtime versus the maintenance saving.
Case 8: Intermediate — EV charging entry
Prompt: A fuel station operator is considering installing rapid EV chargers at 100 sites. Is it worth it?
Data: Capex £120k per charger, 2 chargers per site, margin £0.15 per kWh, 8 sessions per charger per day at 30 kWh each.
Strong answer covers: annual margin per charger (8 × 30 × 0.15 × 365 ≈ £13k); payback of roughly nine years before opex; utilisation sensitivity; ancillary retail spend.
Case 9: Advanced — Utility decarbonisation
Prompt: A mid-sized utility must cut emissions by half within ten years. Build a strategy.
Strong answer covers: an emissions baseline by source, abatement options ranked by cost, regulatory incentives, financing and phasing.
Technology and media
Case 10: Foundation — App subscription pricing
Prompt: A fitness app with 500,000 subscribers at £8 a month wants to raise the price to £10. What happens to revenue if 15% churn?
Strong answer covers: current £4m a month versus 425,000 × £10 = £4.25m; break-even churn of 20%; customer segmentation.
Case 11: Intermediate — SaaS growth slowdown
Prompt: A B2B software company's ARR growth slowed from 40% to 15%. Diagnose.
Data: New-customer ARR stable; net revenue retention fell from 120% to 98%.
Strong answer covers: retention as the driver; investigating churn and expansion by segment; customer success interventions.
Case 12: Advanced — Streaming service bundling
Prompt: A streaming service is considering bundling with a mobile operator. Evaluate.
Strong answer covers: acquisition cost savings, revenue share, cannibalisation, churn effects and negotiating leverage.
Financial services and private equity
Case 13: Foundation — Bank branch closures
Prompt: A UK bank wants to close 20% of its branches. What should it consider?
Strong answer covers: cost savings, customer migration to digital, vulnerable customer impact, regulatory and reputational risk.
Case 14: Intermediate — Paper LBO on a business services firm
Prompt: A sponsor buys a business at £30m EBITDA at 9x with 5x leverage. EBITDA grows to £42m in five years, exit at 9x, and £60m of debt is repaid. Calculate MOIC and approximate IRR.
Workings: EV £270m; debt £150m; equity £120m. Exit EV £378m; debt £90m; exit equity £288m. MOIC 2.4x; IRR roughly 19%.
Strong answer covers: a clear calculation and returns attribution (EBITDA growth versus deleveraging).
Case 15: Advanced — Commercial due diligence on a gym chain
Prompt: A PE fund is considering buying a budget gym chain. Assess the investment case.
Strong answer covers: market growth and saturation, membership economics (yield, churn, utilisation), site rollout returns, competitive intensity, downside cases and value creation levers.
How do you track progress?
After each case, score yourself 1–5 on structure, maths, insight, synthesis and communication. Move up a difficulty level when you consistently score 4 or more.
FAQ
Are these cases from real firm casebooks?
No. They were written originally for this library, and all data is fictional.
Can I share these cases?
Yes. Please link back to this page.
Which difficulty should I start with?
Foundation, unless you've already completed 10 or more cases.
How do I practise these alone?
Use an AI interviewer to reveal data when you ask, or write the data on cards to reveal only when needed.
