ZS Case Interview Examples and Practice Cases (2026)

A ZS case interview asks you to work through a real business challenge and show how you structure it, calculate and recommend, and ZS publishes three practice cases on its careers site: an airline expansion, a pharma pricing problem and a sunscreen launch. This page works nine cases in that shape. Two are ZS's own airline and sunscreen cases decoded with their exhibits, and seven are worked from original or library data, covering built on the Sales and Value & Access work that ZS lists on its capabilities page.

The ZS case interview guide owns the process, the frameworks and the walkthrough of ZS's SINHA drug pricing case, and the IQVIA case interview guide covers the closest peer. This page is the reps: the prompt, the questions to ask, a structure, the math step by step and a recommendation with a number and a risk. Every original case is labelled as one, and none is a ZS case.

ZS-style practice cases at a glance

How a ZS case works: ZS says you work through a real business challenge to show how you structure problems, develop solutions, apply feedback and think creatively, with no single perfect answer. ZS publishes no round-by-round format, so the facts below are labelled by source.

• Official, rounds: typically two to four, depending on role, level and region, with behavioral interviews, case interviews and subject matter expertise interviews on your past projects, quality of work and stakeholder communication (ZS interview process page).
• Official, written exercise: certain roles take an online assessment that ZS calls a written exercise, testing logical, quantitative and qualitative reasoning, plus big data concepts and coding languages for some roles.
• Official, practice cases: three, covering an airline, a pharma pricing problem and a consumer goods launch, each with reveal answers.
• Reported, case style: candidate-led, with a structured case that has exhibits and an unstructured one, such as where to open a dry cleaner (Hacking the Case Interview).
• Reported, written case: a chart packet and a presentation, 45 minutes with 8 to 10 slides per CaseBasix and 30 to 45 minutes with 5 to 6 charts per MConsultingPrep.

Start free now: MedSuite Technologies Hospital Software Pricing is a McKinsey-style pricing case where a hospital software company tests tiered prices. It has 8 questions, 3 with math, 2 exhibits, and a median of 20 minutes across 18 completed voice runs. An AI interviewer runs it out loud, shows each exhibit when you reach it and scores the debrief. Your first full case is free when you create an account. A free account also gets one full run in every simulator inside the app: one complete run of each of our four McKinsey Solve practice formats (Red Rock, Sea Wolf, SFL Classic and SFL Island), a full Casey-style case, a full CCA-style diagnostic and a complete Bain SOVA-style diagnostic.

Case (style, industry)	Quant difficulty	Qualitative difficulty	The math you run	Median time
MedSuite Technologies Hospital Software Pricing (McKinsey, hospital software). 8 (3 with math), 2 exhibits.hospital softwareQuant difficulty mediumQualitative difficulty medium20 min· 18 voice runsTry free	medium	medium	Revenue at each price point, tiered pricing	20 min18 voice runs20 min, 18 voice runs	Try free
Biopharma Outsourcing to Mexico (BCG, biomanufacturing). 7 (1 with math), 1 exhibit.biomanufacturingQuant difficulty easyQualitative difficulty medium22 min· 14 voice runsTry free	easy	medium	Variable cost per unit, annual savings	22 min14 voice runs22 min, 14 voice runs	Try free
Mustard Clinic (McKinsey, healthcare). 8 (3 with math), 2 exhibits.healthcareQuant difficulty hardQualitative difficulty mediumFewer than 10 runsTry free	hard	medium	Average stay, cost saving, freed capacity	Fewer than 10 runsFewer than 10 runs	Try free
Montoya Soup (McKinsey, consumer packaged goods). 8 (4 with math), 6 exhibits.consumer packaged goodsQuant difficulty hardQualitative difficulty hardFewer than 10 runsTry free	hard	hard	Line margins, cannibalization, price scenarios	Fewer than 10 runsFewer than 10 runs	Try free

Three are adapted from consulting club casebooks (Wharton and Kellogg) and the fourth was written for Road to Offer. The library has no case in ZS's own style, so these are matched by case type to ZS's pharma, healthcare, pricing and consumer goods work, and none is ZS's own material. More are in the case library, 92 cases in all. Every debrief scores seven categories: structure (25% of the score), quantitative analysis (20%), business judgment (15%), and problem understanding, exhibit reading, communication and synthesis (10% each), with feedback on every question. Median times come from completed runs between June 25 and September 22, 2026, and count runs, not people.

What does a ZS case interview look like?

ZS describes its case interview as a real business challenge in which you structure the problem, develop solutions, apply feedback and think creatively, and it says there is no perfect answer. Interviewers look at how you approach the challenge, how you respond to feedback and whether you bring new ideas. ZS adds that the number of rounds is typically two to four and that your recruiter will walk you through the process for your role.

Now run one out loud the way a ZS interviewer expects:

The three formats below are what ZS and candidate sites describe. Only the first two come from ZS itself, so check the third against your invitation:

The behavioral interview is separate. ZS also lists subject matter expertise interviews about your past projects, quality of work and stakeholder communication, and one prep site reports they mostly go to experienced and technical hires (Hacking the Case Interview). If a case is candidate-led, you open with your own structure and ask for the data you need, so every case below starts from your structure and then asks for numbers. That covers the interviewer-led version too.

Does ZS publish practice cases?

Yes: ZS's careers site lists three practice cases, each with reveal answers, and they are the closest public match to what ZS asks. The three are All-Star Airlines exploring new markets, Zoltners, a small pharmaceutical company, pricing a new product (the SINHA case), and Consumer Goods Company launching a new sunscreen formula. ZS's practice page says the cases show the kind of work and impact you can have at ZS and that there is no perfect answer.

We decode the airline and sunscreen cases below as Cases 1 and 2, with the values from their exhibits, because those exhibits are where the math lives. The SINHA pricing case is walked through step by step in the ZS case interview guide, so we do not repeat it here. Read each ZS case on ZS's site first, work it, then compare your answer with ours.

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15 steps

• Learn how to caseGuided learning · 35 min
• The Case Interview MethodLesson · 8 min
• Profitability & Turnaround: AfrihealSkill drill · 5 min
• Profitability & Turnaround: Berty BankSkill drill · 5 min

How much math is in a ZS case interview?

ZS publishes no breakdown of how much of the interview is math, so the evidence is its own three practice cases, and they need only percentages, multiplication and division. In the airline case you divide fixed costs by a per-ticket margin and then by a market size. In the sunscreen case you multiply a population by a usage rate, a share and a unit profit. In SINHA you total a cost per dose and check a production capacity.

What makes the math feel heavy is the exhibit: a table with seven rows and three columns, a line chart with six series, and units that switch between millions and billions. Candidate sites add that ZS cases are more quantitative than a typical strategy case (CaseBasix, with no data behind it) and that exhibits carry more rows (Hacking the Case Interview). One prep site reports guesstimates and market sizing in the oral case (MConsultingPrep), and another reports an unstructured case with almost no data (Hacking the Case Interview). Online assessment lengths range from about 40 to 90 minutes across those two sites, which is too wide to plan around, so use your invitation.

The practical answer is to drill three things: exhibit reading, two-to-five-step arithmetic with explicit units, and a patient-funnel estimate from scratch. The case interview math practice page, the market sizing walkthrough and guesstimate questions cover the techniques.

Which case types does ZS ask, and which case covers each?

ZS's capabilities page names nine areas, and the seven other cases below sit closest to Sales and Value & Access, with the two decoded cases covering market entry and a consumer launch. The table maps each case type to the nearest named capability. It is our matching, not a ZS list of case types.

All numbers in Cases 3 to 5 and 7 to 9 are assumptions made up for practice. Case 6 uses the numbers in its own library exhibit. Cases 1 and 2 use the values in ZS's own exhibits, as we read them on November 12, 2026. State your own assumptions out loud in an interview, exactly as the cases do.

The loop to run on every case

Read only the prompt, write your structure and your questions, then open the solution. The cases below use the same five parts so you can compare each part to your own:

1. Prompt: the client, the decision and the constraint.
2. Clarifying questions: what you would ask, and what the interviewer would plausibly say.
3. Structure: two to four branches that you can test, not a template.
4. The math: every step substituted, with units.
5. Recommendation: a decision, one number, one risk and a next step.

If you have never run a case, the pharma case interview, life sciences consulting case interview, healthcare case interview and pricing strategy cases pages teach the frameworks. This page is for reps.

Case 1: ZS's All-Star Airlines case, decoded

Prompt (ZS practice case one). All-Star Airlines is a US subsidiary of All-Star Airlines Group, known for friendly staff and high-quality meals. It is profitable, holds $5 billion in cash and forecasts slow US growth, so it wants to expand into new markets. ZS asks for a recommendation on whether to proceed and where. This is ZS's case, not an original one, and the exhibit values below are ZS's.

Clarifying questions. What does "expand" mean, a new route network or a new country? What is the time limit for payback? ZS's third question answers the second: the client wants to break even within three years of entering a market. Ask whether market sizes stay flat over those three years, because that changes the share you need.

Structure. ZS's own answer to the first question is a profit framework with hypotheses, so build it around what the exhibit gives:

The data (ZS's exhibit).

The math. Break even means the margin on tickets sold covers the investment plus three years of operating costs.

1. Market A: fixed costs are $2.4B + 3 x $1.0B = $5.4B, and the margin per ticket is $400 - $100 = $300. Tickets needed: $5.4B / $300 = 18M. The three-year market is 3 x 120M = 360M, so the share is 18M / 360M = 5%.
2. Market B: fixed costs are $4.5B + 3 x $1.5B = $9.0B, the margin is $400 - $200 = $200, and tickets needed are $9.0B / $200 = 45M. The three-year market is 450M, so the share is 10%.
3. Market C: fixed costs are $1.5B + 3 x $0.75B = $3.75B, the margin is $350 - $100 = $250, and tickets needed are 15M. The three-year market is 300M, so the share is 5%.
4. These match ZS's answer: A and C need about 5%, B needs 10%. Watch the units: billions divided by dollars gives millions of tickets if you write $5.4B as 5,400M.
5. Extension, not in ZS's reveal: with 10, 15 and 5 competitors, an equal split gives a fair share of 1 / 11 = 9.1% in A, 1 / 16 = 6.3% in B and 1 / 6 = 16.7% in C. Market A asks for about half its fair share, Market C for under a third, and Market B for 10% against a fair share of 6.3%. The assumption is that rivals are equal and the market stays flat for three years.

Recommendation. Enter A or C and rule out B, which has the highest cost per ticket, the most rivals and the steepest share requirement. A gives the best margin at $300 a ticket, while C is the cheaper entry at $1.5B in a high-growth market with five competitors, and growth lowers the share needed in later years. The risk is that a premium airline brand may not carry a $350 fare in C, so test price sensitivity before choosing. Next step: ask for the growth rate in C and the fare All-Star's product edge can hold.

Practice a market entry case for ZS

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Case 2: ZS's sunscreen launch case, decoded

Prompt (ZS practice case three). Consumer Goods Company (CGC) is a major US consumer goods company. Its skincare division relies on Summertime Sunscreen (Product A), which holds 2% of the US sunscreen market. CGC has developed Product B, a new formulation, and is preparing to launch it. ZS asks five things in order: the questions to answer before launch, how the product data should shape marketing, which customer segments to target, the profit to expect and how to choose channels. This is ZS's case and the numbers are ZS's.

Clarifying questions. What is Product B and how does it differ from Product A? Who competes, and what is the price? ZS's reveal says Product B is an oil-free formula for daily use, while Product A suits the beach, and Product B is priced about four times higher. At a price of $24.99 that implies about $6 for Product A, which is our arithmetic, not ZS's.

Structure. Work the five questions as one chain: product and value proposition, segment choice, size of prize, channel.

Reading the exhibits. Two of them carry the case, and the second is where the profit math starts:

• Use of Summertime Sunscreen: among its users, the beach is the top use for 43% of men, 63% of women and 50% of nonbinary respondents, while daily skincare is 2%, 2% and 10%. Product B's daily-use positioning targets a use that Product A barely serves, which is why ZS says cannibalization is low.
• Weekly sunscreen wearers by group, 2015, 2022, 2025: men 18 to 29 went from 9% to 12% to 26%, women 18 to 29 from 22% to 25% to 29%, women 30 to 64 from 33% to 34% to 34%, and nonbinary 18 to 29 from 15% to 17% to 25%. Men 18 to 29 are the fastest riser over the last three years, up 14 points.

The math. ZS sizes one segment, US men aged 18 to 29, from the exhibits.

1. People aged 18 to 29, all genders: 53M (ZS's population exhibit).
2. Men are about half: 53M / 2 = 26.5M, which ZS rounds to 27M.
3. Regular users: 27M x 26% = 7M. The 26% is the 2025 weekly-wearer rate for men 18 to 29 in the line chart, so the exhibit, not a guess, supplies it.
4. Buyers at a 2% share of those users: 7M x 2% = 140,000.
5. Profit per unit: $24.99 - $9.99 = $15. At one purchase a year: 140,000 x $15 = $2.1M a year.
6. Check the rounding: 26.5M x 26% x 2% x $15 is about $2.07M, so the rounding costs about 1.6% and does not change the answer. Extension: each extra point of share is 70,000 buyers and about $1.05M, so the share assumption moves the result more than any other input.

Recommendation. Launch Product B as a daily-use, premium product with its own positioning, and start with the segments ZS ranks highest, nonbinary and women aged 18 to 29 and 30 to 64, with US men 18 to 29 as the sized example. The profit for one segment is only about $2M a year on these inputs, so the case for launching rests on adding segments and on repeat purchase. The risk is the 2% share, which has no evidence behind it, so ask for a comparable launch before committing channel spend.

Practice a consumer growth case for ZS

ConsumerMedium

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Case 3: Sizing a specialty sales force

Prompt. A pharma client is launching a specialty drug in the US and asks how many sales reps it needs and where they should spend their calls. This is an original practice case, not a ZS case. All numbers are practice assumptions.

Clarifying questions. How many physicians can prescribe the drug, and how are they ranked? How many calls can a rep make in a year, and what does a rep cost? Is there evidence of how sales respond to more calls? You get the data below. A rep makes 5 calls a day for 200 field days, which is 1,000 calls a year, and costs $250,000 a year in total.

The gross margin a call earns is flat at $700 in B and $150 in C. In A it falls as calls rise:

Structure.

• Workload: physicians x calls each, divided by calls a rep can make.
• Value: what each call earns, by segment.
• Cost: what each call costs, compared with what it earns.
• Deployment: move calls to where the next call earns most.

The math.

1. Calls today: A 2,000 x 24 = 48,000, B 4,000 x 12 = 48,000, C 6,000 x 4 = 24,000, so 120,000 calls. Reps: 120,000 / 1,000 = 120, costing 120 x $250,000 = $30M.
2. Margin today: A 2,000 x $34,000 = $68.0M, B 48,000 x $700 = $33.6M, C 24,000 x $150 = $3.6M, so $105.2M, or $75.2M after rep cost.
3. Cost per call: $250,000 / 1,000 = $250. C returns $150 a call, so each C call loses $100: 24,000 calls lose $2.4M. B returns $700, so keep it.
4. Marginal margin in A: from 12 to 24 calls, ($34,000 - $20,000) / 12 = $1,167 a call. From 24 to 36, ($42,000 - $34,000) / 12 = $667. From 36 to 48, ($44,000 - $42,000) / 12 = $167. Add calls while the next call earns more than $250: go to 36 and stop.
5. Redeploy: stop calling C, and take A from 24 to 36 calls, which is 2,000 x 12 = 24,000 calls. Total calls stay at 120,000 and reps stay at 120.
6. New margin: A 2,000 x $42,000 = $84.0M, B $33.6M, C $0, so $117.6M, or $87.6M after rep cost. That is $12.4M a year more: A gains $16.0M and dropping C gives up $3.6M.

Recommendation. Keep 120 reps and move them from low-potential to high-potential physicians: no calls to C, 36 a year to A, 12 to B. It earns about $12.4M more a year on these inputs with no new headcount. The risk is the response curve, which is an estimate, and C includes physicians who may become high prescribers, so pilot the new call plan in a few territories for two quarters before rolling it out, and keep a light digital touch on C.

Case 4: Sizing the patient funnel for a new treatment

Prompt. A pharma client expects approval of a treatment for a chronic condition and asks how large the US revenue opportunity could be at peak. This is an original practice case, not a ZS case. All numbers are practice assumptions, not epidemiology.

Clarifying questions. Adults or all ages? Moderate to severe patients only? Is the price a list price or a net price? Is peak a share of treated patients or of all patients? You get: US adults, 260M; list price $48,000 a patient a year; rebates and discounts take 37.5% of list; patients take the drug 70% of the year on average.

Structure. A funnel from population to revenue, because every drop between steps is a different lever:

The math.

1. Patients: 260M x 0.5% = 1.3M.
2. Diagnosed: 1.3M x 60% = 780,000.
3. Qualify: 780,000 x 25% = 195,000.
4. Treated with an advanced therapy: 195,000 x 40% = 78,000.
5. Our patients at peak: 78,000 x 20% = 15,600.
6. Net price: $48,000 x (1 - 37.5%) = $30,000 a patient year, and at 70% of the year on drug that is $21,000.
7. Peak net revenue: 15,600 x $21,000 = $327.6M.
8. Sensitivity: if 75% are diagnosed instead of 60%, every later step scales by 75 / 60 = 1.25, so revenue is about $410M, up $82M.
9. Cross-check: 78,000 treated patients across 3,000 specialists is 26 each. Ask whether that is plausible for a specialist's caseload.

Recommendation. Plan on about $330M of net revenue at peak, and present it as a range, about $246M at a 15% peak share (327.6 x 15 / 20) to about $410M with 75% diagnosed, with diagnosis and share as the swing factors. The risk is a 20% share against competitors with a head start, so ask for a comparable launch curve and size the sales force against the 15,600 patients, not the whole funnel.

Case 5: Pricing against a competitor's rebates

Prompt. The client's new specialty drug lists at $60,000 a patient year. Payers want rebates, and a competitor's formulary position is at stake. Should the client pay a bigger rebate to commercial insurers to win preferred placement? This is an original practice case, not a ZS case. All numbers are practice assumptions.

Clarifying questions. Who pays, and what share of patients does each payer cover? What rebate does each ask for? How many patients are treated, and how do shares change with placement? You get the table below, a treated market of 78,000 patients, a 12% share without placement and an 18% share with it, and a competitor listing at $50,000 with a 35% rebate. Assume cost of goods is small and the same per patient in both options.

Structure.

• Price: list price, then net price after rebates by payer.
• Volume: patients and share under each option.
• Competition: the rival's net price.
• Value: what the extra rebate buys and what it costs.

The math.

1. Weighted rebate A: 50% x 30% + 30% x 20% + 15% x 45% + 5% x 0% = 15% + 6% + 6.75% + 0% = 27.75%. Net price: $60,000 x (1 - 0.2775) = $43,350.
2. Weighted rebate B: 50% x 45% + 6% + 6.75% = 22.5% + 6% + 6.75% = 35.25%. Net price: $60,000 x 0.6475 = $38,850, which is 10.4% lower than A.
3. Patients: A 12% x 78,000 = 9,360, and B 18% x 78,000 = 14,040.
4. Revenue: A 9,360 x $43,350 = $405.8M, and B 14,040 x $38,850 = $545.5M, so B is $139.7M higher.
5. Break-even: B matches A when it reaches 405.8M / $38,850 = 10,444 patients, which is a 13.4% share. The same answer comes from the price ratio: $43,350 / $38,850 = 1.116, so B needs 11.6% more patients than A, and 9,360 x 1.116 = 10,444.
6. Competitor: its net price is $50,000 x (1 - 0.35) = $32,500. Option B's net price is 38,850 / 32,500 = 1.195, about 20% above the rival's, so the client needs a value story (efficacy, outcomes) beyond price.

Recommendation. Pay the bigger commercial rebate, because placement only has to lift the share from 12% to 13.4% to pay for itself and the case assumes 18%. The risk is that the 18% is the number least backed by evidence and the rival may respond with a bigger rebate, so ask for formulary access data and check that the extra rebate still pays at a 14% share, just above the 13.4% break-even.

Practice a pricing case for ZS

AutomotiveHard

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Case 6: Pricing hospital software by customer size

This case is the library's MedSuite Technologies Hospital Software Pricing, worked from its own exhibits. It is a Value & Access style question: what should a product cost, and does one price beat a menu? It is not a ZS case. Set your price before you read the table.

The prompt. MedSuite is a healthcare IT startup with a new cloud electronic health records platform for US hospitals. It needs the annual subscription price that maximizes first-year revenue. How should it price the product?

Clarifying questions. Is first-year revenue contract value or recognised cash? Does willingness to pay change with hospital size? What does it cost to serve one hospital? The case gives about 5,800 US hospitals, a 6 to 12 month sales cycle, a variable cost of about $30K a hospital a year, $15M of fixed costs, and a CEO who prefers one price in year one but is open to tiers. A ZS interviewer would also ask whether the price is a list or a net price after discounts, and the case treats it as one annual price.

Structure. Demand at each price, then price against competitors, then what can be sold in year one. Only the first part is arithmetic, and the exhibit supplies it.

The math. Exhibit 1 counts the hospitals whose maximum willingness to pay reaches each price, so revenue potential is price times that count. Each row is a separate scenario, so never add the rows.

The best single price is $150K. Raising it to $200K loses 1,400 small hospitals and $60M of annual potential.

Now test a menu. Take the best listed price for each size band, large hospitals at $350K, medium at $200K and small at $150K, using the band counts behind the exhibit.

That is $890M against $660M for one price, about 35% more, before the cost of selling three prices or any discounting between bands.

Recommendation. Launch at $150K, the best single price at $660M of potential, and test a size-based menu in the first cohort, because $890M on paper needs conversion and renewal data the case does not give. As a viability check, at 10% penetration 440 customers at $150K contribute 440 x $120K = $52.8M against $15M of fixed costs. The risk is that the $150K list is not what hospitals pay once they negotiate, which is the gross to net question Case 5 works.

Practice the full hospital software pricing case

HealthcareMedium

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Case 7: When does a drug launch pay back?

Prompt. A mid-sized pharma company plans to launch a new drug and the CFO wants payback within three years. The launch plan spends heavily on a field team, marketing and patient support. Does the plan meet the CFO's test, and what has to be true? This is an original practice case, not a ZS case. All numbers are practice assumptions.

Clarifying questions. What counts as payback, cash after contribution margin or after all costs? Is spending fixed, or does it scale with sales? Over what horizon, and is it discounted? You get: payback means cumulative contribution after launch spend turns positive, undiscounted; contribution margin is 80% of revenue; launch spend is a plan.

Structure.

• Cash in: revenue ramp and margin.
• Cash out: launch spend by year.
• Test: cumulative cash and the year it turns positive.
• Stress: what if the ramp is slower.

The math.

1. Year 1: 0.8 x $40M - $120M = -$88M. Cumulative: -$88M.
2. Year 2: 0.8 x $140M - $80M = +$32M. Cumulative: -$56M.
3. Year 3: 0.8 x $260M - $60M = +$148M. Cumulative: +$92M. Payback falls in year 3, at 2 years plus 56 / 148, which is 2.4 years, assuming cash arrives evenly in the year.
4. Stress, revenue 25% below plan every year: year 1 is 0.8 x $30M - $120M = -$96M, year 2 is 0.8 x $105M - $80M = +$4M for a cumulative -$92M, and year 3 is 0.8 x $195M - $60M = +$96M for a cumulative +$4M. Payback is 2 years plus 92 / 96, which is 3.0 years, exactly the CFO's line.
5. Threshold: revenue over three years is $40M + $140M + $260M = $440M, and spend is $260M, so 0.8 x $440M x s = $260M gives s = 260 / 352 = 74%. Revenue can come in 26% under plan before the three-year test fails.

Recommendation. The plan passes with room: 2.4 years on plan and a 26% revenue cushion. Approve it, but release the year 2 and year 3 spend against launch milestones, so spend follows the ramp instead of the plan. The risk is the ramp, because the first two years bring in $180M against $200M of spend, so ask for the evidence behind $140M in year 2, such as comparable launches.

Practice a launch case for ZS

EducationMedium

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Case 8: An incentive plan that pays too much

Prompt. A pharma sales force of 100 reps has a target incentive of $60,000 each, so the incentive budget is $6.0M. After the year, finance says payouts ran well over budget while sales came in only a little over plan. What went wrong and what should change? This is an original practice case, not a ZS case. All numbers are practice assumptions.

Clarifying questions. How is attainment measured, and how are quotas set? What does the payout curve look like, and is there a cap? You get this result for the year:

Structure.

• Cost: total payout against budget.
• Results: average attainment and sales against plan.
• Plan design: quotas, the payout curve and the cap.
• Fairness: whether the top results reflect effort or territory.

The math.

1. Payout by band: 10 x 0 = $0, 30 x 0.75 x $60,000 = $1.35M, 40 x 1.30 x $60,000 = $3.12M, and 20 x 2.00 x $60,000 = $2.40M. The total is $6.87M, which is 114.5% of the $6.0M budget.
2. Sales against plan: (10 x 80% + 30 x 95% + 40 x 110% + 20 x 135%) / 100 = (800 + 2,850 + 4,400 + 2,700) / 100 = 107.5%.
3. Payout grew 14.5% on 7.5% more sales, so the incentive cost per dollar of sales is 114.5 / 107.5 = 1.065, or 6.5% above plan.
4. Quota check: 40 + 20 = 60 of 100 reps beat quota. When most reps beat it, quotas may have been set too low or a few territories had a windfall.
5. Lever, a 160% cap in place of 200%: the top band becomes 20 x 1.60 x $60,000 = $1.92M, which saves $0.48M. The total is $6.39M, or 106.5% of budget against 107.5% of plan sales, a ratio of 0.99.
6. Cost to the top group: 2.00 - 1.60 = 0.40 of target, or $24,000 per rep in the over-120% band.

Recommendation. First check whether quotas tracked territory potential, since 60% above quota points at quota setting, not at effort. Use a 160% cap as the interim fix, which brings cost in line with sales at a $24,000 a year cost to each of the top 20 reps. The risk is attrition among the best performers, so pair the cap with a quota reset for next year and a clear message about why.

Case 9: Reading a territory data packet

Prompt. A client has 100 reps in five regions and asks where to add or move headcount. You have a one-page packet. This is an original practice case, not a ZS case, and it has the shape of the chart packets that candidate sites describe in the written case. All numbers are practice assumptions.

Structure. Compute three ratios before forming a view:

• Productivity: sales per rep.
• Penetration: sales as a share of potential.
• Load and headroom: potential per rep, and unfilled potential per rep.

The math. Totals first: 100 reps, $260M of sales and $780M of potential, so the average load is $7.8M of potential per rep.

1. Sales per rep: North $60M / 20 = $3.0M, South $50M / 25 = $2.0M, East $54M / 15 = $3.6M, West $75M / 30 = $2.5M, Central $21M / 10 = $2.1M.
2. Penetration: North 60 / 150 = 40%, South 50 / 200 = 25%, East 54 / 90 = 60%, West 75 / 300 = 25%, Central 21 / 40 = 52.5%.
3. Load: West has $10.0M of potential per rep against an average of $7.8M, and South has $8.0M.
4. Split by potential: each region's share of the $780M times 100 reps gives 19.2, 25.6, 11.5, 38.5 and 5.1, rounded to 19, 26, 12, 38 and 5. That says West needs about 8 more reps and Central about 5 fewer.
5. Read the exhibit before acting on that rule: East has the highest sales per rep at $3.6M and 60% penetration, so it is nearly saturated, with only $2.4M of unfilled potential per rep, and its reps are likely the most productive. South is different: its load of $8.0M a rep is near average, yet it sells the least per rep, $2.0M, with 25% penetration. Adding reps to South treats a quality or access problem as a headcount problem.

Recommendation. Move 4 reps into West, 2 from East and 2 from Central, then compare West's sales per rep with the $2.5M baseline after two quarters, and investigate why South underperforms before adding anyone there. The proportional rule would move more, but it ignores response, and East's reps may sell more than the potential suggests. The risk is that potential is an estimate, so ask how it was built before moving people on it.

How do you turn these cases into a prep plan?

Run each case once cold, then repeat only the step that broke. Cases 1, 2 and 9 train reading exhibits, Cases 3, 4 and 8 train capacity and funnel arithmetic, and Cases 5 to 7 train price, volume and payback. The sequence below uses all nine in about a week, and it works whether your interviews are candidate-led or interviewer-led.

For the process, the frameworks and ZS's SINHA case, use the ZS case interview guide and the interview prep page for ZS. If a written case is on your invitation, the written case interview guide and case interview data interpretation cover the packet skills Case 9 uses. For the break-even and launch logic in Cases 1 and 7, read the break-even analysis case and new product launch case pages, and see pricing case interview example for Case 5. The top life sciences consulting firms page compares ZS with its peers, and case interview examples collects worked cases from other firms.

Turn this guide into a ZS plan

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15 steps

• Learn how to caseGuided learning · 35 min
• The Case Interview MethodLesson · 8 min
• Profitability & Turnaround: AfrihealSkill drill · 5 min
• Profitability & Turnaround: Berty BankSkill drill · 5 min

Sources and further reading (checked November 12, 2026)

• ZS: Interview process (two to four rounds, behavioral, case, subject matter expertise, online assessment called a written exercise for certain roles, two to four weeks after a video interview)
• ZS: Case interview practice (three practice cases, no perfect answer, what interviewers look for)
• ZS: Practice case one, All-Star Airlines (setup, questions and the market exhibit decoded as Case 1)
• ZS: Practice case three, Consumer Goods Company sunscreen (setup, questions, exhibits and reveal answers decoded as Case 2)
• ZS: Practice case two, SINHA drug pricing (walked through in the ZS case interview guide)
• ZS: Capabilities (nine named capabilities, including Sales, Value & Access and Strategy & Transformation)
• ZS: Careers (career tracks and the note that ZS helps candidates prepare)
• ZS Interview Process, Hacking the Case Interview (candidate-reported structured and unstructured cases, written case and assessment details; a prep site, not ZS; page updated September 29, 2026)
• ZS Associates case interview, CaseBasix (candidate-reported rounds, candidate-led cases, written case with 8 to 10 slides; a prep site, not ZS)
• ZS Associates case interview, MConsultingPrep (reported written case, oral case and guesstimates; page footer dated 2022; a prep site, not ZS)