Book your next three unfamiliar cases with time between them to use the feedback. Give each one a purpose: establish your current gaps, test a repair, then see whether it holds with a different interviewer. That will tell you more about the practice you need than chasing someone else's total.
For planning, expect a sustained routine of live cases and focused work between them. I would start with two partner sessions a week, then adjust the balance as your weaknesses become clear. When the skills work separately but fall apart together, add full cases. When one recurring error keeps breaking the analysis, repair it directly.
Count the work accurately
Keep separate records for cases you attempted as candidate, cases you gave, short drills and demonstrations you watched. All can help, but they develop different things.
Giving a case teaches you to recognise clear explanations and useful questions. Watching a demonstration can reveal how a candidate handles a difficult moment. Neither shows that you can solve the same problem independently after seeing its answer.
Mark prior exposure. Replaying a familiar case is useful when you want to practise a correction. Choose new material when you want to assess whether that correction transfers.
Expect live practice to take sustained work. Use your recent performance to decide what to do next: another full mock, a targeted correction or a fresh test of something you have repaired.
Inspect the last three attempts
Choose unfamiliar cases from more than one setting, and include a different reviewer if possible. For each, record where you needed help and whether you recovered.
| Part of the case | What you want to see |
|---|---|
| Opening | You identify the decision and clarify information that changes the approach |
| Structure | Your branches explain how you will answer this particular question |
| Quantitative work | You choose a valid setup, track units and check the result |
| Interpretation | You explain what the finding means for the client's decision |
| Adaptation | You use new information and respond to the interviewer's question |
| Conclusion | You choose an action and support it with the strongest findings |
| Conversation | Another person can follow and challenge your reasoning |
This is a review method for your preparation. Use it to find patterns rather than calculate a synthetic pass score.
Quick Prioritisation Drill
A bike-repair chain's monthly profit has slipped. The owner can fund a fix for only one recurring problem this quarter.
| Problem | Times per month | Profit lost each time |
|---|---|---|
| Missed customer bookings | 80 | £25 |
| Redone faulty repairs | 5 | £300 |
| Late parts deliveries | 30 | £90 |
Which problem should the owner fix first to recover the most monthly profit?
Look beyond whether the case was finished
A completed case can hide a lot of help. An interviewer may have supplied the equation, pointed to the decisive exhibit row or suggested the final recommendation. Record those moments so you can target the missing skill.
Differentiate a rescue hint from normal interaction. A clarification or the next question in an interviewer-led case is part of the conversation. The useful question is whether you could perform the reasoning requested at that stage.
Similarly, notice successful recovery. Catching a unit error, correcting it and updating the conclusion demonstrates something valuable. A practice review that treats every slip identically misses the difference between a recoverable mistake and a persistent conceptual gap.
Compare two practice records
Imagine two candidates. Arun has attempted 32 cases. In his last three, he repeatedly needed a reminder to include the cost of serving extra customers. Maya has attempted 17. In her last three, she handled different industries, explained the economics independently and corrected one arithmetic slip before using the result.
Arun needs a focused repair before another similar mock. Maya's next work can emphasise variety, realistic delivery and personal-experience preparation. Their totals are useful history; the recent answers determine the next action.
For Arun, use this original exercise. A service charges £100 per customer, has £60 variable cost per customer and £20,000 fixed cost. With 1,000 customers, profit is £20,000. A promotion attracts 200 additional customers at the same price but costs £10,000 to run.
The extra customers generate £8,000 contribution, so profit falls by £2,000 after the promotion cost. The campaign needs 250 additional customers to cover its cost. Arun should explain that logic, then solve a different problem without being reminded to calculate contribution.
Quick Answer Repair Drill
A parcel firm will copy one depot's working methods at a new site. A candidate ends the case with this recommendation.
- Candidate's recommendation
- Copy North, which has handled twice the deliveries
| Depot | Deliveries since opening | On-time rate, months 1 to 3 |
|---|---|---|
| North | 40,000 | 88%, 84%, 79% |
| South | 20,000 | 93%, 94%, 95% |
What is the main flaw in this recommendation?
Let the review choose the next session
If you cannot explain the underlying relationship, use a lesson and a small worked exercise. If you understand it but execute inconsistently aloud, use focused spoken drills. If isolated skills are sound but you lose the thread in a full conversation, use a mock and review its transitions.
If feedback conflicts, show the same prompt and your reasoning to an experienced reviewer. Ask them to identify the decisive issue. Avoid collecting a third overall opinion without examining the evidence behind the first two.
Track feedback and return to weak sections. Make each review alter your next practice session.
Add variety when familiarity starts helping too much
A regular partner is useful because they recognise your habits. They may also understand an explanation that a new listener would find incomplete. Periodically practise with someone who has not heard your usual phrasing.
Change the problem as well: a different industry, a nonprofit objective, a capacity constraint or an unfamiliar exhibit. Keep the underlying task appropriate to your interview. Difficulty for its own sake can distract from the behaviours you need to perform consistently.
The practice-group guide shows a rotation that gives you variety without rebuilding your schedule every week.
When the interview is close, protect useful practice
Review the largest unresolved issue and the confirmed format. Spend the remaining time on a correction you can actually use, personal questions and logistics. If extra mocks are making your reviews rushed and your thinking tired, reduce the volume.
You are in a stronger position when recent unfamiliar cases show that you can make progress independently, use feedback and explain a supported decision. Keep checking those behaviours. They give you a practical reason to continue, change or taper your preparation, whichever number is in the case-count column.
Frequently asked questions
Measuring your practice honestly
Is there a set number of cases I need before I am ready?
No. Your recent performance tells you more than your total. In the article's example, Arun has done 32 cases but still needs reminders about the cost of serving extra customers. Maya has done 17 and is solving unfamiliar cases independently. Arun needs a focused repair, while Maya can move on to more variety.
Do cases I give as the interviewer count towards my total?
Record them separately. Giving cases trains you to recognise clear explanations and useful questions. However, it does not show that you can solve problems yourself, so keep these sessions apart from the cases you attempt as the candidate.
Does watching case demonstrations count as practice?
Count it, but separately from attempts. A demonstration can show how a candidate handles a difficult moment. Once you have seen the answer, though, solving that same problem yourself does not prove you could have done it independently. Short drills also belong in their own record.
Which cases should I include when I review my last three?
Use unfamiliar cases from more than one setting and, if possible, include a different reviewer. For each case, note where you needed help and whether you recovered. In the opening, for example, check whether you identified the decision and asked about information that changes your approach.
I finished the case. Does that mean it went well?
Not necessarily. Finishing a case can hide how much help you received. The interviewer may have supplied the equation, pointed you to the deciding row in an exhibit or suggested the recommendation. Note each of those moments so you can practise the skill that was missing.
Do clarifications or interviewer prompts count against me?
Normal interaction does not. A clarification, or the next question in an interviewer-led case, is part of the conversation. A rescue hint is different: it is the interviewer stepping in when you could not move forward. Record rescue hints, because they show which skill to work on.
Choosing your next session
When should I stop doing mocks and study the concept instead?
When you cannot explain the underlying relationship. Then a lesson and a small worked exercise will help more than another full case. If you understand the idea but apply it inconsistently when speaking, use focused spoken drills instead.
My individual skills are fine, but I lose the thread in full cases. What helps?
Do a full mock and then review the transitions between stages. Drilling isolated skills will not help much if each one already works on its own. The problem is holding them together across a conversation, and only a complete case lets you practise that.
What should I do when different reviewers give conflicting feedback?
Show the same prompt and your reasoning to an experienced reviewer. Seeing both together lets them judge which comment applies to your actual answer. Another mock with a new case would only add more feedback without settling the disagreement.
Is it a problem if I always practise with the same partner?
It can be. A regular partner knows your habits, which is useful, but they may also follow explanations that a new listener would find incomplete. Practise with someone who has not heard your usual phrasing from time to time, so you can check that your reasoning comes across clearly.
Should I look for harder cases to stretch myself?
Look for variety rather than difficulty. Try a different industry, a nonprofit objective, a capacity constraint or an unfamiliar exhibit. Keep the underlying task appropriate to your actual interview, because making cases harder for its own sake does not prepare you any better.
Just before the interview
Should I cram extra mocks in the days before my interview?
Only if they stay useful. If extra mocks are rushing your reviews and tiring your thinking, cut back. Spend the time on your largest unresolved issue, the confirmed interview format, a correction you can actually use, personal questions and logistics.
What shows I am in a strong position going into the interview?
Your recent unfamiliar cases show that you can make progress independently, use feedback and explain a supported decision. That evidence matters more than your total number of cases. Keep checking it in your remaining sessions instead of assuming earlier progress has held.