Cut each Big problem stop using the McKinsey method
An AI coach based on MECE and Barbara Minto's Pyramid Principle. Give Claude a vague or overwhelming problem, get a complete Issue Tree back. With hypotheses per branch, MECE check, and 80/20 prioritisation.
Is the drop due to fewer customers?
High impactLower average order value per customer?
Impact mediaHigher churn of existing customers?
High impactEnd of season clearance: what's the timing?
Impact layerWhy MECE structuring before you come up with solutions
90%: A great deal of time is wasted on unstructured brainstorming when tackling a major issue. With MECE, you first break the problem down into sub-solutions that do not overlap but together cover the whole. Only then do you come up with solutions.
Faster to the right question
Instead of hours of brainstorming, you'll get an Issue Tree in 10 minutes that shows which sub-question needs to be answered first.
No overlap, no gaps
The skill ALWAYS checks whether branches are mutually exclusive (no overlap) and collectively exhaustive (together covering 100% of the problem). Standard McKinsey approach.
Hypothesis-driven
Each branch holds a falsifiable hypothesis. You don't collect data without a purpose; you test hypotheses. A proven approach from consulting.
Direct concrete action
Every analysis concludes with a single action, taking a maximum of one working day. No 30-page reports that disappear into a drawer.
How to Claude skill Works
Four fixed phases. First, structure; then, solutions can follow. The order is important: without a MECE Issue Tree, you'll start solving the wrong problem.
What the skill does for you
Your problem will first be rewritten into a Situation, Complication, and Resolution question. The vague becomes sharp.
The root question is divided into 2-5 branches. Algebraically, process-wise, stakeholder or segment-wise depending on the type of issue.
No vague analysis. Each branch will receive a falsifiable statement that you can later test with data.
The skill highlights which 20% branches are expected to yield 80% in the response. That’s where you start.
The 4 phases
Problem definition
SCR formula: situation now, what disturbs it, and what question needs to be answered.
MECE decomposition
The main question is broken down into sub-questions that do not overlap and together cover 100%.
Hypothesis per tree
Each branch has a verifiable statement with impact, required evidence, and owner.
Priority and first action
The 80/20 branches are marked and the skill provides one concrete action of a maximum of one working day.
Example Issue Tree output
This is what complete output looks like. You give the skill a problem in one sentence, this is what you get back.
Problem: monthly turnover has fallen by 19% over three months
Resolution question: why has monthly revenue dropped from 80k to 65k over the past three months?
Is the decrease due to fewer customers?
Hypothesis: the number of new customers per month has decreased because we have less advertising budget.
Are fewer leads coming in?
Hypothesis: leads have fallen by 30% since Q1.
1.2 Converting leads worse?
Hypothesis: Conversion rate has dropped due to poorer intake.
2. Is the decrease due to lower order value?
Hypothesis: Existing customers are buying less per order due to the price increase.
3. Does the decrease lead to higher churn?
Hypothesis: existing customers are cancelling due to a better competitor.
With or without MECE Coach
The difference between an hour of unstructured brainstorming and ten minutes with an Issue Tree.
Without structure
- x You immediately start brainstorming solutions, often for the wrong problem
- x Actions overlap and gaps remain undiscovered
- x Collecting data without a hypothesis, i.e. without direction
- x No prioritisation, so everything is equally important (= nothing is important)
- x Two weeks later, you're still nowhere.
With the skill
- v First, clarify the root question using the SCR formula
- v MECE check guarantees no overlap and no gaps
- v Hypotheses per branch, so every measurement has a purpose
- v 80/20 priority dictates what you start with tomorrow
- v One concrete action of a maximum of one working day
The Prompt structuring behind the skill
Do you want to reverse engineer the skill yourself or use it as a prompt? This is the core of what the skill does behind the scenes.
You are a MECE Problem Structuring Coach trained on the McKinsey method and the work of Barbara Minto.
Reframe the problem as a Situation, Complication, and Resolution question. The resolution question will be the root of the Issue Tree.
Break down the root cause into 2 to 5 sub-questions. Choose the appropriate MECE structure: algebraic, process-based, stakeholder, segment, 7S, or internal x external.
Each branch has a falsifiable statement with impact (high/medium/low), required evidence, and owner.
Test MECE explicitly. Mark 80/20 branches. End with 1 concrete action of maximum 1 working day.
Frequently Asked questions
MECE staat voor 'Mutually Exclusive, Collectively Exhaustive'. Het is een principe dat wordt gebruikt in probleemoplossing en analyse om ervoor te zorgen dat alle onderdelen van een probleem worden aangepakt zonder overlappende informatie. * **Mutually Exclusive (Wederzijds exclusief)** betekent dat elk onderdeel van de analyse of oplossing uniek is en niet overlapt met een ander onderdeel. Bijvoorbeeld, als je de bevolking van een stad deelt in leeftijdsgroepen, dan mag een persoon niet in meerdere leeftijdsgroepen vallen. * **Collectively Exhaustive (Gezamenlijk uitputtend)** betekent dat alle mogelijke onderdelen van het probleem of de situatie worden meegenomen. Er is geen ruimte voor iets dat buiten de analyse valt. Als je bijvoorbeeld de bevolking van een stad deelt in leeftijdsgroepen, dan moet elke mogelijke leeftijd aanwezig zijn in een van de groepen. **Waarom werkt het?** MECE is effectief omdat het: 1. **Orde creëert:** Het dwingt je om complexe problemen op te splitsen in kleinere, beheersbare, niet-overlappende stukken. Dit maakt het analyseren en oplossen van het probleem overzichtelijker. 2. **Dubbel werk voorkomt:** Door ervoor te zorgen dat de onderdelen elkaar niet overlappen, voorkom je dat je onnodig dezelfde informatie of oplossing meerdere keren bekijkt of aanpakt. 3. **Gaten dicht:** Omdat het 'collectively exhaustive' is, zorgt het ervoor dat je geen belangrijke aspecten van het probleem over het hoofd ziet. Dit leidt tot een completere en robuustere analyse of oplossing. 4. **Betere besluitvorming bevordert:** Met een duidelijk gestructureerd en compleet beeld van een probleem, kun je beter geïnformeerde beslissingen nemen. 5. **Communicatie verbetert:** Een MECE-structuur is vaak gemakkelijker te begrijpen en te communiceren aan anderen, omdat de logische opbouw duidelijk is. Het is een nuttig raamwerk, vooral in consultancy, bedrijfsanalyse en projectmanagement, om ervoor te zorgen dat alle aspecten van een probleem grondig en efficiënt worden onderzocht.
MECE stands for Mutually Exclusive, Collectively Exhaustive. It was introduced by Barbara Minto at McKinsey in the 1960s. It works because it prevents two very common mistakes: double work (overlap between branches) and blind spots (missing branches). With MECE, you can be sure that you cover everything without double-analysing.
What kind of problems does this skill work for?
For any large, vague or overwhelming issue. Strategic decisions, revenue declines, customer retention problems, productivity questions, market research, organisational issues. Not for pure fact-finding questions or for problems that take less than 2 hours to resolve.
How does this differ from the Pyramid Principle or SCQA?
The Pyramid Principle (also by Minto) is how you communicate your answer: top-down, governing thought, supported by arguments. SCQA is a narrative structure for the opening: situation, complication, question, answer. MECE is underneath that: how you break down the problem itself before formulating an answer. They reinforce each other.
Do I need consulting experience to use this?
No. The skill guides you step by step. You enter a problem in plain language, the skill structures it according to the McKinsey method and explains why the branches are MECE. You don't need to have read Minto, Rasiel or Conn.
Does this skill also work in Claude Desktop and Claude Code?
Yes. The skill is a standard Claude skill (SKILL.md format). You can use it in Claude Desktop, Claude Code, Claude API, and in Claude for Chrome. Download the zip, unpack it into your skills folder.
What sources is this skill based on?
Three standard works. Barbara Minto, The Pyramid Principle (1973). Ethan Rasiel, The McKinsey Way (1999). Charles Conn and Robert McLean, Bulletproof Problem Solving (2018). All in the bibliography at the bottom of SKILL.md.
Can I adapt the skill for my own domain?
Yes, MIT licence. Open SKILL.md, add domain-specific MECE structures (for example, for your own industry), save as a new skill. Please provide feedback on what you have adjusted, so everyone improves.
Download de MECE Coach
Free, MIT licence, no registration. Unpack the zip in your Claude skills map and activate per project.
AI MECE Problem Structure Coach Skill
SKILL.md with the complete McKinsey method approach. Ready for Claude Desktop, Claude Code and Claude API.
Download zip (4 KB)Sea Thought frameworks for Claude
Structuring using MECE is stronger when combined with other frameworks. Three suitable skills from TheSEO.
AI Pyramid Principle Writer
Communicate your MECE findings top-down as Barbara Minto intended: governing thought first, then supporting details.
View skillAI 5 Whys Analyst
Once the correct MECE branch has been chosen, use the 5 Whys to drill down to the root cause within that branch.
View skillAI Pre-Mortem Analyst
Before you carry out your 80/20 action: a pre-mortem shows how it can go wrong and what you need to prepare.
View skill