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Should a warehouse near Rotterdam automate its picking?

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 online retailer's warehouse near Rotterdam, the Netherlands, employs 50 pickers, each costing EUR 50,000 a year including taxes and benefits. A system that brings shelves to the pickers costs EUR 3 million installed, lasts about 10 years, and costs EUR 200,000 a year to run (maintenance, software, energy). At the planned volume it does the work of 16 pickers. Staff turnover is 20 percent a year. Should the retailer buy it? (Fictional company, 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.

Payback = one-off cost / (labour saved minus running cost)
- Yearly net saving at the planned volume
- Payback against a 10-year life
- Key: Volume risk: the saving if volume is lower
- People: can turnover absorb the change?

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: Labour saved
What a strong candidate does: 16 pickers at EUR 50,000.
Labour saved a year (EUR): 16 × 50,000 = 800,000
Step 2: Net saving
What a strong candidate does: Minus EUR 200,000 a year to run the system.
Net saving a year (EUR): 16 × 50,000 - 200,000 = 600,000
Step 3: Payback
What a strong candidate does: EUR 3 million divided by EUR 600,000 a year.
Payback (years): 3,000,000 ÷ 600,000 = 5
Step 4: At half the volume
What a strong candidate does: If orders come in at half the plan, the system replaces only 8 pickers, but still costs EUR 200,000 a year to run.
Payback at half volume (years): 3,000,000 ÷ (8 × 50,000 - 200,000) = 15
Step 5: Volume needed to pay back within its life
What a strong candidate does: To repay EUR 3 million in 10 years it must save EUR 300,000 a year net, so EUR 500,000 of labour, which is 10 pickers out of the planned 16.
Share of planned volume needed (fraction): ((3,000,000 ÷ 10 + 200,000) ÷ 50,000) ÷ 16 = 0.625
Step 6: People who leave anyway
What a strong candidate does: 20 percent of 50 pickers leave each year.
Pickers leaving a year: 50 × 0.2 = 10
Step 7: Time to absorb 16 roles
What a strong candidate does: 16 roles, with 10 people leaving a year on their own.
Years to absorb the change through turnover: 16 ÷ 10 = 1.6

The recommendation to listen for

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

Buy it only if the retailer is confident volume will stay well above two thirds of plan. At the planned volume it saves EUR 600,000 a year and pays back in 5 years, well inside its 10-year life. But it is a bet on volume: at half the plan, payback stretches to 15 years, longer than the system lasts; it needs about 62.5 percent of planned volume just to repay its cost (before allowing for the time value of money, which makes the bar higher). On people, turnover of 10 pickers a year can absorb the 16 roles in about 1.6 years if hiring is paused, and some pickers can be retrained to run and maintain the system. Next step: test the volume forecast and agree the staffing plan with employee representatives before signing.

Risks a strong answer names: Volume falls or shifts to items the system cannot handle; Breakdowns stop picking entirely unless some manual capacity is kept; Pausing hiring for 18 months strains the remaining team in peak season.

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.