Interviewer view · keep this screen to yourself
Standard: Wenlan Charge: home chargers in a large Chinese city
You run the case. Read the prompt, answer questions from the notes below, and share data only when the candidate asks for it or gets stuck. Score at the end.
Case timer
00:00
1. Read the prompt aloud
Read it slowly, then pause. Let the candidate ask questions before they structure.
First, estimate how many home chargers for electric cars are installed each year in one large Chinese city. Then: Wenlan Charge, a charger maker, has been offered a partnership with a group of car dealers. Should it accept?
Format note: Difficulty: Standard. Format: market-sizing opener, then a business question. Industry: Electric vehicles and equipment. Region: Mainland China. Interview length: about 30 minutes. The company is fictional and all figures are illustrative.
2. Answers to clarifying questions
Give these answers only if the candidate asks. If they ask something not listed, give a sensible answer or say it does not matter here.
If asked: Which city, and how many people?
Answer: A large eastern Chinese city of about 20 million people, with about 2.5 people per household (rounded, illustrative).
If asked: How many households own a car, and how often do they buy one?
Answer: About 40 percent own a car and replace it about every 8 years.
If asked: What share of new cars are new energy vehicles (battery electric and plug-in hybrid cars), and who can install a charger?
Answer: Use about half of new cars (illustrative). About 60 percent of those buyers have a fixed parking space where a charger can be installed.
If asked: For the business question, what are the numbers?
Answer: A charger costs Wenlan CNY 1,400 including installation. It sells at CNY 2,500 and wins about 12 percent of installs today. A car-dealer group offers to recommend Wenlan to buyers for a commission of CNY 300 per charger, which Wenlan expects would raise its share to 20 percent.
3. The hypothesis a strong candidate states
Listen for an early, testable guess like this one. It does not need to match word for word.
Only new energy vehicle buyers with a parking space need a home charger. My hypothesis is that the market is around one hundred thousand chargers a year, and that the dealer deal pays if it raises share enough to cover the commission.
4. A model structure
Compare the candidate's structure with this one. A different split can be just as good if it is clean and fits the problem.
- Size the yearly market, then compare contribution with and without the deal
- Households x car owners x purchases a year x new energy share x parking space
- Contribution today: share x margin per charger
- Key: Contribution with the dealer deal, and the share it needs
- What car makers do next
5. The working, step by step
Each step shows how a strong candidate works it out. Share a new fact from it only when the candidate asks or is stuck, and let them do the math: the result in the dark box is what they should reach.
Step 1: Households
What a strong candidate does: 20 million people at 2.5 people per household.
Households: 20,000,000 ÷ 2.5 = 8,000,000
Step 2: Cars bought by households each year
What a strong candidate does: 40 percent own a car, replaced every 8 years.
Cars bought a year: 20,000,000 ÷ 2.5 × 0.4 ÷ 8 = 400,000
Step 3: Home chargers a year
What a strong candidate does: Half are new energy vehicles, and 60 percent of those buyers have a parking space.
Home chargers a year: 20,000,000 ÷ 2.5 × 0.4 ÷ 8 × 0.5 × 0.6 = 120,000
Step 4: Contribution today
What a strong candidate does: 12 percent share and CNY 1,100 of margin per charger.
Contribution today (CNY a year): 120,000 × 0.12 × (2,500 - 1,400) = 15,840,000
Step 5: Contribution with the dealer deal
What a strong candidate does: 20 percent share, with CNY 300 of commission off each charger.
Contribution with the deal (CNY a year): 120,000 × 0.2 × (2,500 - 1,400 - 300) = 19,200,000
Step 6: Share the deal needs
What a strong candidate does: Candidate: "The deal pays if contribution with the commission beats today's CNY 15.84 million."
Break-even share (%): 120,000 × 0.12 × (2,500 - 1,400) ÷ (120,000 × (2,500 - 1,400 - 300)) × 100 = 16.5
Step 7: Curveball: free chargers from car makers
What a strong candidate does: Interviewer: "Some car makers now include a free home charger with half of new cars." Candidate: "The market Wenlan sells to halves. With the dealer deal:"
Contribution with the deal, half market (CNY a year): 120,000 × 0.5 × 0.2 × (2,500 - 1,400 - 300) = 9,600,000
Step 8: Supplying the car makers
What a strong candidate does: Interviewer: "One car maker asks Wenlan to supply its free chargers at CNY 1,700 each. Wenlan could win 30 percent of those in this city." Candidate: "Dealer channel plus supply deal:"
Total contribution (CNY a year): 120,000 × 0.5 × 0.2 × (2,500 - 1,400 - 300) + 120,000 × 0.5 × 0.3 × (1,700 - 1,400) = 15,000,000
The recommendation to listen for
At the end, say: "The CEO walks in. What is your recommendation?"
About 120,000 home chargers a year are installed in a city like this. Wenlan should accept the dealer deal. First, at a 20 percent share the deal lifts yearly contribution from about CNY 15.8 million to CNY 19.2 million. Second, it pays as long as share rises above 16.5 percent, which leaves a margin of safety against the expected 20 percent. Third, if car makers start including free chargers, the dealer channel alone would fall to about CNY 9.6 million, so Wenlan should also bid to supply car makers: at CNY 1,700 per charger and a 30 percent share, total contribution would recover to about CNY 15 million. Sign the dealer deal for one year and review the share it actually delivers.
Risks a strong answer names: Dealers may push rival chargers that pay a higher commission; Car makers may choose one national charger supplier.
Next steps: Agree a share target and review date with the dealer group; Meet the purchasing teams of the three largest car makers selling in the city.
Strong versus weak
A strong answer
Built the sizing chain with clear assumptions, found the break-even share for the deal, and responded to the curveball with a new channel rather than only a smaller number.
A weak answer
Sized the market from total population without asking who has a parking space, then accepted the deal because "more share is always better."
Score the candidate
Score each criterion from 1 to 5. A 2 or a 4 sits between the descriptions.
This case has no exhibit. Score Exhibit reading on how the candidate used the data you gave them: did they pick out the number that matters and say what it means?
Total
0 out of 25
Score all five criteria to see the band and the feedback template.