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A clinic pharmacy in Singapore with one pharmacist

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.

A clinic pharmacy in Singapore has one pharmacist. Each prescription takes 4 minutes on average. 12 prescriptions arrive an hour. The clinic expects patients to rise to 13.5 an hour next year. How long will patients wait, and what should the clinic do? (Fictional clinic, illustrative figures.)

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.

Wait in queue = service time x utilization / (1 minus utilization)
- Capacity = 60 minutes / minutes per prescription
- Key: Utilization = arrivals / capacity
- Options: cut the service time, or add staff at peaks

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: Capacity
What a strong candidate does: 60 minutes divided by 4 minutes each.
Prescriptions an hour: 60 ÷ 4 = 15
Step 2: Utilization today
What a strong candidate does: 12 arrivals against a capacity of 15.
Utilization today (fraction): 12 ÷ 15 = 0.8
Step 3: Wait today
What a strong candidate does: 4 minutes x 0.8 / 0.2.
Average wait today (minutes): 4 × 0.8 ÷ (1 - 0.8) = 16
Step 4: Utilization next year
What a strong candidate does: 13.5 arrivals against 15.
Utilization next year (fraction): 13.5 ÷ 15 = 0.9
Step 5: Wait next year
What a strong candidate does: 4 minutes x 0.9 / 0.1.
Average wait next year (minutes): 4 × 0.9 ÷ (1 - 0.9) = 36
Step 6: With a technician who does the labelling
What a strong candidate does: Service time falls to 3 minutes, so capacity is 20 an hour and utilization 13.5 / 20.
Average wait with a technician (minutes): 3 × (13.5 ÷ 20) ÷ (1 - 13.5 ÷ 20) = 6.23

The recommendation to listen for

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

A rise of 12.5 percent in patients more than doubles the average wait, from 16 to 36 minutes, because the pharmacist goes from 80 to 90 percent busy. Adding a technician to label and pack medicines cuts the service time to 3 minutes and the wait to about 6 minutes. Do not judge this team by how busy it is: a pharmacist who is 90 percent utilized looks efficient on paper while patients wait over half an hour.

Risks a strong answer names: The rule gives averages; the lunchtime peak will be worse; A technician costs money every hour, so check the cost against the value of shorter waits.

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.