Assessment Centre: Hour-by-Hour Walkthrough

An assessment centre is a half-day or full-day selection event in which several candidates rotate through a series of work-like exercises (typically a group discussion, a case study, an in-tray exercise, a role-play, a presentation and a competency interview) while trained assessors score each candidate independently against a published competency framework. It is not a competition between the candidates in the room: everyone can pass and everyone can fail. Employers run assessment centres because online tests predict reasoning ability but say little about how you behave in a room, under pressure, with other people. The day is designed to show them exactly that.

What Is an Assessment Centre?

The format dates back to military officer selection and is now the standard final stage for graduate programmes, management intakes and many senior hires. The underlying logic is behavioural sampling: rather than asking you what you would do, the employer builds a small, controlled version of the job and watches what you actually do. Each competency in the framework is deliberately measured in at least two different exercises (leadership might be observed in the group exercise and probed again in the competency interview) so that a single bad twenty minutes does not sink you and a single lucky moment does not carry you.

The exercise mix changes by employer, role and country, and virtual assessment centres are now as common as on-site ones. Shell runs a full-day centre with a group exercise, case study, presentation and senior manager interview. KPMG runs a half-day centre built around a group exercise, a written exercise and a partner interview. Unilever runs a virtual discovery centre. Deloitte's centre combines a case study, a collaborative exercise and a competency interview. The exercise names differ; the competencies underneath them barely move.

• See the full exercise taxonomy, sample questions and strategies on our assessment centre category page.
• For a firm-specific worked example of the same day, read the Deloitte assessment centre guide.
• Company processes stage by stage: Shell, Unilever and KPMG.

The Day at a Glance

The timeline below is a composite full-day centre. Half-day centres cut two or three exercises (most often the role-play and the presentation) and virtual centres compress the breaks. Treat the clock times as a shape, not as a promise.

1. 108:30: Arrival and registration. Coffee, name badges, a short introduction from the recruitment team, and an unstructured twenty minutes with the other candidates. Nothing is formally scored yet; impressions are already forming.
2. 209:00: Briefing. The schedule, the ground rules, and usually a line about how the day is scored. Ask your logistics questions here, not in the middle of an exercise.
3. 309:15: Group exercise. Four to eight candidates, one business brief, 30 to 45 minutes, two or three assessors watching in silence.
4. 410:30: Case study or written analysis. A data pack and a business question. 30 to 60 minutes of preparation, sometimes ending in a written recommendation, sometimes feeding the later presentation.
5. 511:30: In-tray / e-tray exercise. An inbox of 10 to 20 emails and documents, 30 to 60 minutes, and far too much to do. Prioritisation is the test.
6. 612:30: Lunch. Informal, with recruiters and often junior employees at the table. Not scored on a form; absolutely noticed.
7. 713:15: Role-play. 15 to 30 minutes with a trained actor playing an unhappy client, an underperforming team member or a difficult stakeholder, plus a short preparation window.
8. 814:15: Presentation. Five to ten minutes of delivery on the case you prepared, followed by five to ten minutes of questions from assessors who will push back.
9. 915:15: Competency interview. 45 to 60 minutes, structured, behavioural, with probing follow-ups. Your STAR story bank does its work here.
10. 1016:15: Wrap-up. A closing Q&A, an explanation of the timeline, and you leave. Decisions typically land within one to three weeks.

Every Exercise: What It Measures and How It Is Scored

The table below is the single most useful thing to internalise before your centre. Read across each row: the exercise is only the vehicle, the competency in the second column is what is actually being bought, and the last column is what the assessor writes on the form.

08:30: Arrival, Registration and the Icebreaker

You arrive, you are given a badge and a schedule, and you spend twenty unstructured minutes in a room with the people you are about to do a group exercise with. Recruiters are in the room. Nobody has a scoring form open, but the person who spent the coffee break silently on their phone and then tried to lead the group exercise thirty minutes later has already created a contradiction the assessors can feel.

• What assessors are scoring: nothing formally. What they are forming is a baseline impression that colours how ambiguous behaviour later in the day gets read.
• What good looks like: learn three names, ask three people what they applied for, be the person who makes the room slightly less awkward.
• Common mistake: treating the other candidates as competitors from the first handshake. They are your group-exercise team in half an hour, and the assessors will see exactly how that transition goes.
• Practical: arrive 15 minutes early, bring a pen and a notebook, and eat breakfast. Assessment centres are long, and fatigue does most of its damage after 14:00.

09:15: The Group Exercise

Four to eight candidates get a brief (allocate a budget across three projects, agree a market-entry recommendation, choose which of five products to discontinue) and a deadline that is deliberately too short. Two or three assessors sit outside the circle, say nothing, and write. Some centres assign roles; most run leaderless, which means the group must organise itself, and how it does that is half the assessment.

• What assessors are scoring: contribution quality, listening, influence without dominance, and whether the group reaches a decision.
• What good looks like: proposing a structure early, summarising where the group has landed, timekeeping out loud ('ten minutes left, two points to cover'), and inviting the quiet candidate in.
• Common mistakes: interrupting, repeating a point that has already been accepted, winning the argument at the cost of the task, and staying silent because the room is loud. Assessors can only score what they observe. Silence is scored as nothing.
• Group exercises appear in interview processes too: see our group interview training for the same behaviours in a different frame.

10:30: The Case Study or Written Analysis

You get a pack (a client brief, a P&L, a market chart, a couple of internal emails) and a question. Depending on the employer you produce a written recommendation, a set of slides, or notes you will present after lunch. The pack always contains more data than you need and at least one number that quietly contradicts the obvious conclusion.

1. 1Spend the first five minutes structuring, not reading. Write the question you are answering at the top of the page, then two or three buckets you will use to answer it. A structure you commit to beats a perfect structure you never finish.
2. 2Then read with the structure in hand. You are hunting for evidence that fills buckets, not absorbing a pack.
3. 3Quantify one thing. A margin, a payback period, a cost gap. One number in the recommendation separates you instantly from candidates presenting adjectives.
4. 4Lead with the answer. One sentence, up front, then the reasoning. Never build up to a conclusion.
5. 5Name two risks and what you would do about them. Stating the risks to your own recommendation is scored as commercial maturity, not as weakness.
6. 6Say what you would check next. 'To validate this I would want churn by segment' shows you know what you do not know.

11:30: The In-Tray / E-Tray Exercise

You are dropped into a fictional manager's inbox: ten to twenty emails, memos, a calendar and a couple of attachments, with 30 to 60 minutes and far more work than fits. Modern e-tray versions are interactive: new emails arrive mid-exercise and change your priorities, which is the point. This is the exercise candidates most often underestimate, because it looks like administration and scores like judgement.

• What assessors are scoring: prioritisation logic, delegation, written communication, and whether you escalate the things that need escalating.
• What good looks like: an explicit triage pass in the first three minutes; short, structured replies that lead with the decision; and a visible note of what you consciously chose not to do.
• Common mistakes: working through the inbox top to bottom, writing beautiful long emails to the first three items and never reaching item twelve, and burying a risk instead of flagging it upward.
• The judgement being tested here is the same judgement an SJT measures: practise it at situational judgement.

12:30: Lunch (Yes, You Are Still Being Observed)

Lunch is presented as a break, and in one sense it is: no assessor is filling in a competency form over a sandwich. But recruiters and junior employees eat with you, they are asked afterwards whether anything stood out, and 'would I put this person in front of a client' is a question every professional services firm answers partly at lunch. The honest framing is this: lunch is not scored, but it is not neutral either.

• What good looks like: talk to people, ask junior employees real questions about their first year, eat something, and stay off your phone.
• Common mistakes: interrogating recruiters about salary and promotion timelines, criticising another candidate's performance in the group exercise, drinking alcohol if it is offered, or disappearing to revise your presentation notes alone.
• Use it deliberately: the people at your table are the best source you will ever get for the 'do you have any questions for us?' moment at the end of the day.
• Energy management is a real competency here. Most candidates dip after lunch, and the exercises after lunch (role-play, presentation, interview) are the ones that carry the most weight.

13:15: The Role-Play

You are given a briefing pack (you are the account manager, the client is unhappy, here is what went wrong) and 15 to 30 minutes to prepare. Then you walk into a room with a trained actor who is briefed to be difficult in a specific, calibrated way. An assessor sits in the corner and scores. The actor is not trying to break you; they are trying to give you something to respond to, and they will escalate if you fold immediately or if you steamroll them.

• What assessors are scoring: listening, empathy, questioning, holding a defensible position under pressure, and closing on a concrete next step.
• What good looks like: open by asking, not by defending. Let the actor state the problem fully, reflect it back in your own words, then move to what you can and cannot do, and be specific about both.
• Never promise what you cannot deliver. Conceding everything to end the discomfort is the single most common failure, and it is scored as poor commercial judgement rather than as kindness.
• Close explicitly: 'So: I will get you the revised timeline by Thursday, and we will review it together on Friday.' A role-play with no agreed next step is an unfinished exercise.

14:15: The Presentation

Usually five to ten minutes on the case you analysed in the morning, sometimes on a topic given cold with 30 minutes of preparation. Then five to ten minutes of questions from assessors whose job is to push back on your reasoning. Being challenged is not a sign that you are failing. The challenge is the exercise.

1. 1Open with the recommendation. One sentence. Then say how you will justify it: 'I will cover the market, the margin and the risks.'
2. 2Signpost every transition. Assessors are scoring structure, and they can only score the structure they can hear.
3. 3Use the numbers you found. Two or three specific figures from the pack, used to make a point, beat ten figures recited.
4. 4Watch the clock and finish early. Running over is scored; finishing at eight minutes of ten is not.
5. 5Handle challenge without collapsing or digging in. 'That is a fair point. It would change my recommendation if X were true; here is why I do not think it is' is close to a perfect answer.
6. 6If you do not know, say so and say how you would find out. Bluffing is transparent to someone who does this every week.

15:15: The Competency Interview

A structured, 45 to 60 minute interview mapped to the same competency framework the rest of the day is scored against. Questions are behavioural ('tell me about a time you had to influence someone without authority') and every answer gets probing follow-ups: why that decision, what was the alternative, what would you do differently. The follow-ups exist to find out whether the story is really yours.

• Use STAR and make the Action about 60% of the answer. Interviewers score what you personally did, so use 'I' and not 'we': a 'we' story is unscoreable, and it is the most common reason a strong candidate gets a low mark here.
• Prepare 8-10 stories across leadership, teamwork, resilience, problem solving, influence, initiative, failure and conflict. One strong story usually answers three different questions once you learn to re-angle it. Our STAR method guide sets out the full structure.
• Quantify every Result. Percentages, euros, hours saved, error rates. If nothing was measurable, say what changed instead.
• Expect a question about the day itself. 'How do you think the group exercise went?' tests self-awareness. Answer honestly and name one thing you would do differently. A candidate who thinks they were flawless is scored as low self-awareness.

16:15: Wrap-Up and What Happens Next

A closing session, a chance to ask questions, and a description of the timeline. After you leave, the assessors hold a wash-up meeting: each one reports the behaviours they observed, evidence is pooled across exercises, and a rating per competency is agreed. This is why consistency matters: a candidate who led decisively in the group exercise and then could not name a single example of leadership in the interview creates a contradiction that the wash-up meeting is specifically designed to catch.

• Ask one good question at the end. Something you could only have learned by being there, ideally from the lunch conversation.
• Decisions normally land within one to three weeks. Chase politely once after the stated date has passed, not before.
• Ask for feedback. Many employers give it on request at this stage, and it is the most accurate information about your performance you will ever get for free.
• Pass marks are not published. Employers do not release cut scores, and the bar moves by role, intake and year. Being comfortably strong across the framework is the only target that means anything.

How Assessors Actually Score You

Assessors are not forming an overall impression and then justifying it. They are running an ORCE loop (Observe, Record, Classify, Evaluate) which is why they write while you talk and say almost nothing. Each behaviour is written down, then matched to a competency, then rated. The practical consequence is blunt: a competency you demonstrate but nobody witnesses does not exist.

Read that table as a matrix: every competency is measured in at least two exercises. That is a design choice, and it is good news for you. A weak group exercise does not sink the day if your case study, presentation and interview all give assessors the evidence they need. Candidates who write the day off after a bad first hour lose marks they had not yet lost.

Mistakes That Cost the Most Marks

• Competing with the other candidates. Assessors score against a fixed framework, not against a curve. Dominating a group exercise reliably loses more marks on collaboration than it gains on leadership.
• Confusing airtime with contribution. The candidate who speaks most is not the one who scores highest. The candidate who moves the group forward is.
• Going silent after a bad exercise. Each exercise is scored independently by different assessors. The next one starts at zero, not at minus one.
• Saying 'we' in the competency interview. The framework scores individual behaviour. A team story with no visible 'I' is unrateable.
• Finishing the in-tray. If you finished it, you almost certainly skimped the reasoning. It is designed to be unfinishable.
• Fading after lunch. The heaviest exercises are usually in the afternoon. Sleep, eat, and pace yourself deliberately.
• Treating lunch as off-duty. Not scored, but not private either.
• Preparing exercises without preparing the framework. Most employers publish their competencies on the careers page. Not reading them is the cheapest mistake on this list to avoid.

Your 2-Week Preparation Plan

1. 1Days 1-2: The framework. Find the employer's published competencies. Write them down. Against each, write the exercise where it will most likely be observed, using the matrix above.
2. 2Days 3-5: Case and structure. Run three timed case studies, each ending in a spoken one-minute recommendation with two risks named. Time yourself at 40 minutes and stop when the clock stops.
3. 3Days 6-7: In-tray and judgement. Practise triage under a clock and drill situational judgement items, which measure the same instinct the e-tray rewards.
4. 4Days 8-10: STAR bank. Write 8-10 stories in bullet form, add the real numbers, then say them out loud on camera and watch them back. This is the highest-return hour of the whole plan and almost nobody does it.
5. 5Days 11-12: Group and role-play rehearsal. Practise the specific phrases: proposing a structure, bringing someone in, summarising, closing on a next step. In a role-play, rehearse saying 'no' pleasantly and specifically.
6. 6Days 13-14: Commercial reading, then rest. Read the business press and the employer's own published insights for your sector. Sleep properly the night before. Cramming reliably lowers assessment-centre performance, because every exercise is a performance under fatigue.

Frequently Asked Questions