Inbox Exercise and Group Case Playbook for Consulting

An inbox exercise (called an in-tray or e-tray in UK recruiting) gives you a simulated mailbox of competing requests and asks you to rank them, choose actions and write short replies against a clock. A group case asks a small team of candidates to agree one decision, and in some formats each person holds a different brief. PwC UK says roles that need planning, organising or coordination can include an in-tray exercise, and EY Australia describes a group activity with two to four other students on a fictional case (official careers pages, checked September 2026). This playbook teaches both with worked examples: a six-email triage and a full group exchange. For how these exercises fit into the whole day, start with the consulting assessment center guide.

What is an inbox or e-tray exercise, and how long does it take?

It is a timed prioritization test dressed as a normal workday. You read emails and attachments, decide what matters, and show that decision through rankings, chosen actions or written replies. Careers publications report lengths from 30 to 80 minutes, and the answer format changes by employer.

What this means for you: GraduatesFirst reports that most e-trays give you more tasks than time, so the ranking is the answer. Finishing every email with a shaky order scores worse than a clear order with the top items done well.

How do you prioritize an inbox with 3C triage?

Read everything once, find the links between emails, score each item on Consequence, Clock and Chain, then choose an action. For the action, targetjobs (August 2025) describes four options for in-tray items: act now, delegate, defer, or drop. 3C tells you the order; those four options tell you what to do with each item.

1. Skim every item first. AssessmentDay (August 2023) also advises reading all items before responding. A later email often changes an earlier one.
2. Draw the chains. Mark any email that cannot be answered until another is handled.
3. Score 3C for each item as high, medium or low.
4. Pick the action: act, delegate, defer or drop.
5. Write replies in ranked order, and give a one-line reason for the order if the format allows it.

Worked example: a six-email inbox at 9:00

This inbox is original practice, not a firm's exercise. You are a junior consultant on a retail pricing project. The client's steering committee meets at 14:00.

• A (08:12), client CFO: "Does the price model exclude the 40 stores we are closing? I lock the board pack at 12:00."
• B (08:30), engagement manager, out today: "Please send the store-closure list to the data team. They can't rerun the model without it."
• C (08:41), data analyst: "Waiting on the closure list. The rerun takes 90 minutes."
• D (08:55), partner: "Can someone draft three talking points for 14:00? End of morning is fine."
• E (09:02), teammate: "Could you check my slide formatting before Friday's internal review?"
• F (09:05), HR: "Please submit your timesheet by end of week."

The trap is the chain. The CFO's 12:00 answer depends on the rerun, the rerun takes 90 minutes, and the rerun needs the closure list. If the list goes out at 09:15, results arrive around 10:45, which leaves time to check them before 12:00. Answer the CFO first, as the most senior sender, and you either guess or run out of time.

The reply to the CFO:

Subject: Store closures in the price model: confirmed figures by 11:30

Hi Sarah, thanks for flagging this. The current run does not yet exclude the 40 closing stores. I have sent the closure list to our data team, and the rerun takes about 90 minutes, so I will send confirmed figures by 11:30, ahead of your 12:00 lock. Until then, please hold the price-impact slide. I am copying our engagement manager for visibility.

It works because it opens with the status, gives a time the sender can plan around, names the dependency without blaming anyone, says exactly what to hold, and keeps the manager informed. It does not promise a number before the rerun exists.

What is a group case with unequal exhibits?

It is a group case where each candidate holds a different slice of the evidence, so nobody can solve it alone. targetjobs' group exercise guide (August 2026) reports that some case exercises give each candidate a different briefing document or role, and the group has to agree despite conflicting views. EY Australia describes a group activity with two to four other students on a fictional case with no single correct answer, and an Accenture Australia recruiter's blog describes about 1.5 hours of group discussion before a 5 to 10 minute presentation (official, checked September 2026).

For general group-case mechanics, including scoring, common mistakes and a 45-minute walkthrough, read the group case interview guide. This section covers the harder variant, where information is unequal.

Which roles help, and what does each one say?

Take a function, not a status. Volunteer for one, do it visibly, and do not spend the exercise designing a team chart. The Accenture Australia blog specifically recommends naming a timekeeper.

The criteria you name at the start shape every later argument, so practice building them before the day.

How should you share an exhibit nobody else has seen?

Use a four-part handoff: Source (what the exhibit covers and its limits), Conclusion (the number that matters), Implication (what it means for the decision) and Uncertainty (what could make it wrong). It keeps your turn short and gives teammates something specific to build on or challenge. When two figures conflict, compare definition, period, population and unit before anyone argues about which is right.

Worked group exchange: launch, pilot or decline

Prompt (original practice). An e-bike rental company is deciding whether to launch a monthly subscription. Aisha holds a customer survey, Ben holds unit economics, and Carla holds repair capacity.

Objective keeper: "We're choosing launch, pilot or decline. Let's test demand, contribution and capacity, then name what would reverse our choice."

Aisha: "Source: a survey of 1,000 existing riders. Conclusion: 20% say they're strongly interested. Implication: there's a launch pool. Uncertainty: it's current customers, not the whole city."

Ben: "Source: unit economics. Conclusion: €18 monthly contribution per subscriber against a €90,000 launch cost. Implication: 500 subscribers for ten months breaks even, because 500 × €18 × 10 = €90,000. Uncertainty: it assumes contribution stays at €18."

Carla: "Source: repair capacity. Conclusion: the team supports 350 extra bikes without hiring. Above that, contractor repairs cut contribution by €6 per subscriber per month. Implication: Ben's €18 only holds up to 350."

You, as integrator: "So the break-even changes. The first 350 subscribers earn 350 × €18 × 10 = €63,000. The next 150 earn 150 × €12 × 10 = €18,000. That is €81,000, still €9,000 short of launch cost at 500 subscribers."

Synthesis owner: "Recommendation: pilot, not full launch. Demand supports a test, but capacity-adjusted contribution does not cover the €90,000 cost at 500 subscribers. The pilot should prove paid conversion and test whether cheaper repairs can hold €18 above 350 bikes. Expand only if both hold."

The group changed its answer when Carla's exhibit changed the economics. That visible integration is what a group exercise is built to show.

Weak lines and stronger lines

In a virtual group case, name the location of evidence ("Carla's exhibit, row three") and summarise what changed rather than narrating your screen.

How do you practice inbox and group skills on your own?

Split the exercise into skills you can rep alone, then combine them with friends. Road to Offer does not simulate inbox or group exercises, but the skills underneath them can be drilled with AI feedback: more than 550 drills across six skill types and 71 full practice cases.

The final interview often asks how you worked in the group. Rehearse that story, with your contribution and what changed, in behavioral interview practice. One-way recorded answers are a separate individual format, covered in the Big Four video interview guide.

Frequently asked questions

What is the difference between an in-tray and an e-tray exercise?

They test the same thing. targetjobs (August 2025) describes the e-tray as the digital equivalent of the paper in-tray, and both put multiple requests and too much information in front of you.

How long is an e-tray exercise?

It varies by employer. targetjobs reported 30 to 80 minutes in August 2025, and GraduatesFirst reported 30 to 60 minutes in August 2026.

Should I try to answer every email?

No. Most e-trays give you more tasks than time, according to GraduatesFirst, so a defensible ranking with strong top replies beats rushed replies to everything.

Do all candidates get the same information in a group case?

Not always. Some formats give each person a different brief or role, as targetjobs reported in August 2026. Share each exhibit with the four-part handoff before debating.

What if the group reaches the wrong answer?

EY Australia says its group case has no single correct answer, and targetjobs reports that group exercises are observed for how you work with others. Show how evidence changed the decision, and make sure your contribution is visible.

Sources

• PwC UK, Assessments: what to expect (official, checked September 2026)
• EY Australia, Early careers recruitment hub (official, checked September 2026)
• Accenture Australia, Group case study tips (official recruiter blog, undated, checked September 2026)
• targetjobs, What are in-tray exercises? (reported, August 2025)
• targetjobs, Example assessment centre group exercises (reported, August 2026)
• targetjobs, What happens at a consulting assessment centre? (reported, August 2026)
• GraduatesFirst, E-tray exercises guide (reported, updated August 2026)
• AssessmentDay, In-tray exercises (reported, updated August 2023)
• The inbox and e-bike examples on this page are original practice scenarios.