PEI and Fit Workbook

What this workbook is for

McKinsey calls it PEI. Bain and BCG want the same muscle with different labels. Deloitte and EY-P will stay in STAR longer. The simulator is for the clock. This file is the bank.

Map every story to two signals. If a story only fits 'I worked hard', it is not a PEI story yet.

Write in this file or a notebook first. Expand the six strongest tomorrow. Then run one timed Deep Dive on the weakest story. A highlight reel dies on the third follow-up.

The four McKinsey signals

How firms differ

Story bank: 12 slots

One sentence each tonight. Expand the six strongest tomorrow. The write-in pages at the back are for the six you keep.

1. Changed someone's mind when they strongly disagreed
2. Led without formal authority
3. Led a team through an ambiguous problem
4. Set an ambitious goal and missed it
5. Developed someone who was struggling
6. Failed and changed the system, not just your mood
7. Delivered under an ugly constraint (time, budget, people)
8. Ethical or values tension you actually felt
9. Structured an ambiguous problem with incomplete data
10. Grit over months, not a heroic weekend
11. Influenced a commercial or pricing call
12. Delivered an unwelcome recommendation and stayed in the relationship

If you are undergrad and 'client' feels fake, use a society, a lab, a store, a family business. The test is ownership, not letterhead.

STAR, compressed

• Situation: one breath. Place, clock, constraint.
• Task: the decision you owned. Not the team's KPI.
• Action: about 60% of the airtime. Meetings, objections, trade-offs. 'I', not 'we'.
• Result: a number, and what you would do again.

Write the action in three beats: the meeting, the objection, the move.

You also need two clocks of the same story. Ninety seconds for a coffee. Three minutes for PEI. If you cannot shrink it, you do not own it yet.

Worked story

Fictional. Steal the shape. Slot 1 — changed someone's mind.

Situation. London, summer 2025, a 40-store grocer. The CFO wanted to delist a private-label soup line. I had ten days and a messy contribution file. Task. I owned the keep-or-kill recommendation for that SKU, not 'helped with the analysis'. Action. Meeting: I put banner-level contribution on one page instead of a 22-tab workbook. Objection: commercial said the line was 'dead' because units were down 8%. Move: I showed the miss was mix, not demand — £1.8m of contribution sat in two banners they were about to cut. Result. The CFO kept the SKU. We killed a national promo that would have bought volume at a 90bp margin hit. If I did it again I would have brought commercial into the first working session, not the last.

Why it survives follow-ups: there is a meeting, an objection, a number, and a regret. The interviewer can ask 'what did you do next?' three times without you repeating the opening.

Follow-up ladder

They will ask 'what did you do?' three times. Pre-load:

1. The next meeting
2. The strongest objection
3. The number or evidence that changed the decision
4. What you would do differently, and why

If you cannot answer 4 without collapsing, the story is still a highlight reel.

Stories that die

• The team won. You cannot name your three moves.
• You were 'passionate' and stayed late. No decision.
• A training course, a certificate, a grade.
• You 'aligned stakeholders' with no named person and no objection.
• The result is 'it went well' or 'they were happy'.
• You switch stories when the follow-up gets hard.

42 prompts

Read one. If you do not have a story in 10 seconds, that slot is empty.

Leadership

1. Tell me about a time you changed someone's mind when they strongly disagreed.
2. Describe a time you led a team through an ambiguous problem.
3. Tell me about a time you made an unpopular call and stuck with it.
4. Give an example of leading without formal authority.
5. Tell me about building a team from scratch.
6. Describe a time you had to cut a workstream or a person from a plan.
7. Tell me about aligning two groups that did not want to work together.
8. Describe a time you owned the outcome after you delegated.

Personal impact

1. Tell me about influencing a decision without authority.
2. Describe a conflict on a team and how you resolved it.
3. When did you simplify a messy problem for a senior audience?
4. Tell me about a relationship that unlocked a result.
5. Describe delivering an unwelcome recommendation.
6. Give an example of coaching someone who was struggling.
7. Tell me about selling an idea with incomplete data.
8. Describe recovering a damaged working relationship.

Drive

1. Tell me about an ambitious goal you missed.
2. Describe grit over months, not a weekend.
3. Tell me about delivering under an ugly constraint.
4. Give an example of results orientation on a tight deadline.
5. Describe operating under distress or a turnaround-like clock.
6. Tell me about a time you raised the bar for a group.
7. Describe keeping going after a public miss.
8. Tell me about taking extra scope because it mattered.

Growth

1. Tell me about learning a new domain in days, not months.
2. Describe a failure that changed the system, not just your effort.
3. Tell me about feedback that stung and what you changed.
4. Describe being wrong in public and the second version of your work.
5. Tell me about working across cultures or countries on a hard problem.
6. Describe going deep on analysis and still telling a simple story.
7. Tell me about the first time you had to manage up.
8. Describe outgrowing a way of working that used to make you look good.

Firm flavour

1. Tell me about influencing a pricing or commercial decision.
2. Describe an operations problem you improved.
3. Tell me about an ethical tension you did not dodge.
4. Describe using data to change a plan already in motion.
5. Tell me about delivering in a matrixed environment.
6. Describe pushing back on a senior person.
7. Tell me about owning an outcome that was at risk.
8. Describe structuring an ambiguous client (or equivalent) problem.
9. Tell me about sizing a bet with incomplete data.
10. Describe a time you chose pragmatic over perfect, and were right.

Self-review rubric

Score 1–5. Anything under 4 gets rewritten.

This week

1. Tonight: fill 12 one-liners.
2. Tomorrow: expand 6 into STAR on the worksheets.
3. Wednesday: timed Deep Dive on the weakest story.
4. Thursday: rewrite from the debrief.
5. Friday: 90-second coffee version and 3-minute PEI version. Same story. Different clock.

Would I put this person in front of a client on Thursday? That is the only question.

Write-in worksheets

Six slots. If a line stays empty, the story is not ready.

Slot 1 — Changed someone's mind

Slot 2 — Led without formal authority

Slot 3 — Ambiguous problem

Slot 4 — Missed an ambitious goal

Slot 5 — Ugly constraint

Slot 6 — Unwelcome recommendation

CoachNed is independent practice. Not affiliated with McKinsey, BCG, Bain, or any firm named here. After the bank is full, run a timed PEI on coachned.com/behavioral.