Interviewer view · keep this screen to yourself

Fiber roll-out in a city in Malaysia

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

Target length:

1. Read the prompt aloud

Read it slowly, then pause. Let the candidate ask questions before they structure.

An operator plans to pass 100,000 homes with fiber in a Malaysian city. Passing each home costs MYR 1,500 and connecting each subscriber costs a further MYR 800. It expects 40 percent of homes to subscribe at an ARPU of MYR 120 a month. Operating costs are 30 percent of revenue. What is the simple payback in years, and how does it change if only 25 percent of homes subscribe?

2. Answers to clarifying questions

This case has no scripted clarifying answers. Answer from the prompt, and say "assume what you think is reasonable" if the prompt does not cover it.

3. 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.

Payback = total build cost / yearly EBITDA
- Build cost = homes passed x cost per home passed + subscribers x cost per connection
- Yearly EBITDA = subscribers x ARPU x 12 x (1 minus operating cost share)
- Sensitivity on take-up rate

4. 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: Subscribers
What a strong candidate does: 40 percent of 100,000 homes.
Subscribers: 100,000 × 0.4 = 40,000
Step 2: Build cost
What a strong candidate does: 100,000 homes at MYR 1,500, plus 40,000 connections at MYR 800, in MYR millions.
Total build cost (MYR millions): (100,000 × 1,500 + 40,000 × 800) ÷ 1,000,000 = 182
Step 3: Yearly revenue
What a strong candidate does: 40,000 subscribers at MYR 120 a month for 12 months.
Yearly revenue (MYR millions): 40,000 × 120 × 12 ÷ 1,000,000 = 57.6
Step 4: Yearly EBITDA
What a strong candidate does: Keep 70 percent after operating costs.
Yearly EBITDA (MYR millions): 57.6 × 0.7 = 40.32
Step 5: Payback at 40 percent take-up
What a strong candidate does: Build cost divided by yearly EBITDA.
Payback (years): 182 ÷ 40.32 = 4.51
Step 6: Payback at 25 percent take-up
What a strong candidate does: 25,000 subscribers: build cost 150 plus 20, EBITDA 25,000 x 120 x 12 x 0.7.
Payback at 25 percent take-up (years): (150 + 25,000 × 800 ÷ 1,000,000) ÷ (25,000 × 120 × 12 × 0.7 ÷ 1,000,000) = 6.75

The recommendation to listen for

At the end, say: "The CEO walks in. What is your recommendation?"

At 40 percent take-up the build pays back in about 4.5 years; at 25 percent it takes about 6.7 years, because the MYR 150 million cost of passing homes is the same either way. The operator should build first where demand is proven (pre-registration, dense housing, weak rival networks), and consider sharing or wholesaling the network to raise use.

Risks a strong answer names: A rival fiber network in the same streets would cut take-up; Fixed wireless access over 5G can compete on price; ARPU may fall if the market enters a price war.

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?

Structuring

1: No clear structure, or a memorized framework that does not fit the problem.
3: A sensible structure, but with some overlap, a gap, or no clear priority.
5: A structure built for this problem, with no overlap and no gaps, a stated hypothesis, and a clear first step.

Math

1: Frequent errors, no units, or needed heavy help to finish.
3: Right answers but slow or messy working, or one error caught late.
5: Accurate and clearly narrated, with units, a sense check, and what the number means.

Exhibit reading

1: Read the chart aloud without finding the number that matters.
3: Found the key number but gave only part of the so-what.
5: Pulled the right number quickly and said what it means for the case.

Synthesis

1: Summarized what was done, with no clear answer.
3: Gave an answer, but with weak reasons or no next step.
5: Answer first, then two or three reasons with numbers, the main risk, and next steps.

Communication

1: Hard to follow: long silences, no signposting.
3: Clear most of the time, with some rambling.
5: Calm and concise, signposted each step, and checked in with the interviewer.

Total

0 out of 25

Score all five criteria to see the band and the feedback template.