MECE is a principle used in problem solving and structuring, particularly in business and consulting. It is an acronym for Mutually Exclusive, meaning that elements do not overlap, and Collectively Exhaustive, meaning that all elements account for all possibilities.
Using the MECE principle provides a number of benefits, including clear thinking, comprehensive analysis, efficiency, and better decision-making.
If you’re unfamiliar with the MECE principle or unsure how you can use it in consulting case interviews and in business, we have you covered.
In this comprehensive article, we’ll cover:
- What is MECE?
- What are examples of being MECE?
- Why is it important to be MECE?
- When do I need to be MECE in a consulting case interview?
- How can I make consulting case interview frameworks MECE?
- Do I always need to be 100% MECE?
- What are tips for being MECE?
If you’re looking for a step-by-step shortcut to learn case interviews quickly, enroll in our case interview course. These insider strategies from a former Bain interviewer helped 30,000+ land consulting offers while saving hundreds of hours of prep time.
What is MECE?
MECE stands for mutually exclusive and collectively exhaustive. It breaks down complex issues into distinct, non-overlapping categories that cover all possibilities. This structured approach promotes clear thinking, comprehensive analysis, and efficient decision-making.
Mutually exclusive: all categories or elements being used to analyze a problem do not overlap. Each item should fit into one and only one category. This ensures that there is no ambiguity or overlap in how elements are classified.
For example, if you were categorizing types of fruits, apples and oranges would be mutually exclusive categories. A fruit cannot be both an apple and an orange at the same time. This clarity helps in structuring information and making sure that each element is placed in the most appropriate category without any ambiguity or overlap.
Collectively exhaustive: all categories or elements being used to analyze a problem cover all possible options without any gaps. This ensures that every possible option or element is accounted for.
For example, if you were categorizing animals, your categories should include all types of animals without leaving any out.
What are examples of being MECE?
MECE Example #1: What do you want to eat for dinner?
Let’s look at a simple MECE example by breaking down a question you likely face each day: what do you want to eat for dinner?
Most people try to answer this question by brainstorming and listing ideas that immediately come to mind:
- Do you want to eat Chinese food?
- Do you want to cook dinner instead?
- Do you want to order take out?
- Do you want to eat pasta?
- Do you want to eat sushi?
- Do you want to eat tacos?
This approach is highly unorganized and makes answering the question of where to eat difficult.
Instead a MECE approach to breaking down the question may look like the following:
This organization is both mutually exclusive and completely exhaustive.
Being mutually exclusive means that none of the different parts overlap with each other.
In this example, eating out and eating in are mutually exclusive. You cannot do both simultaneously, so you can only do one or the other.
Similarly, cooking dinner, ordering pickup, and ordering delivery are mutually exclusive under the category of eating in. You cannot do any of these simultaneously.
Being collectively exhaustive means that all of the different parts account for the entire whole with no ideas or possibilities missing.
In this example, eating out and eating in are collectively exclusive. You will end up choosing one or the other because there are no other options or possibilities If you are going to be eating dinner.
Similarly, cooking dinner, ordering pickup, and ordering delivery are collectively exclusive under the category of eating in. You will end up choosing one or the other because there are no other options or possibilities.
MECE Example #2: Segmenting the population
Let’s look at another MECE example by looking at how we can segment the global population.
If we break down the global population into dog-lovers and cat-lovers, is this MECE?
This segmentation is not mutually exclusive because many people are both dog-lovers and cat-lovers. Additionally, this segmentation is not collectively exhaustive because some people neither love dogs nor cats. Therefore, this segmentation is not MECE.
If we break down the global population into age groups of 0-20 year-olds, 21-40 year-olds, 41-60 year-olds, and 61-80 year-olds, is this MECE?
This segmentation is mutually exclusive because each person can only fall under one of these age segments. However, this segmentation is not collectively exhaustive because it is missing people in the population over the age of 80. Therefore, this segmentation is not MECE.
If we break down the global population into people over 160cm tall and people under 180cm tall, is this MECE?
This segmentation is not mutually exclusive because people between 160cm and 180cm would fall under both categories. However, this segmentation is collectively exhaustive because it covers all possible heights. Overall, this is not MECE.
If we break down the global population into people that make less than $40,000, between $40,000 and $80,000, and over $80,000, is this MECE?
This segmentation is mutually exclusive because there is no overlap. If someone makes $40,000, they would fall in the second category. If someone makes $39,999.99, they would fall in the first category.
If someone makes $80,000, they would fall in the second category. If someone makes $80,000.01, they would fall in the third category.
Therefore, this segmentation is MECE because it is mutually exclusive and completely exhaustive.
Other examples of MECE
Here are other examples of being MECE.
1. Value chain: supplier, manufacturer, distributor, and retailer
2. Ways to increase profit: increase prices, increase quantity sold, decrease variable costs, and decrease fixed costs
3. Ways to enter a market: enter organically, enter through a partnership, and enter through an acquisition
4. Time horizon: short-term, medium-term, and long-term
5. Geographies: North America, South America, Europe, Asia, Africa, Australia, and Antarctica
6. Economic class: lower-class, middle-class, and upper-class
7. Forms of transportation: land transportation, sea transportation, and air transportation
8. Sales: business-to-business and business-to-consumer
9. Synergies: revenue synergies and cost synergies
10. Ways to price: pricing based on costs, pricing based on value provided, and pricing based on competition
Why is it important to be MECE?
Being MECE is important for several reasons:
- Clear thinking: MECE encourages clear and structured thinking. It helps break down complex problems into manageable, distinct components
- Comprehensiveanalysis: ensures that you're considering all relevant factors without any redundancy or gaps. This leads to a more comprehensive understanding of the situation
- Efficiency: It reduces the risk of duplicating efforts or analyzing the same information multiple times. This can save time and resources
- Better decision-making: MECE helps in making informed and well-rounded decisions by considering all possible options and avoiding overlooked aspects
- Communication: When you present information in a MECE manner, it's easier for others to understand and follow your logic. This is particularly important in professional settings
- Problem solving: It provides a structured approach to problem-solving, which can lead to more effective solutions
- Reduced bias: It can help reduce cognitive biases that might occur when information is not categorized properly
- Risk management: By ensuring that all possible options are considered, you're less likely to overlook potential risks or opportunities
- Goal alignment: MECE helps align goals and strategies with the available resources, making it easier to allocate resources effectively
- Project management: It aids in planning and managing projects by breaking them down into distinct, manageable tasks or components
- Innovation and creativity: MECE can stimulate innovative thinking by forcing you to consider all potential options, even those that might not be immediately obvious
Overall, being MECE promotes systematic and thorough analysis, which is helpful for consulting, business, problem-solving, and decision-making. It's a principle that fosters efficiency, clarity, and effectiveness.
For consulting case interviews, being MECE provides three tremendous advantages.
1. MECE frameworks are much more efficient. There is no duplication of work since all of the different parts are mutually exclusive from one another and do not overlap.
2. MECE frameworks guarantee that you do not miss anything. Since the different parts are collectively exhaustive, no idea or possibility will be missing from the framework. By using a MECE framework, you will have confidence that the answer is in the framework somewhere.
3. The MECE principle facilitates brainstorming. Most people approach problems by brainstorming a list of ideas and going through them. The MECE principle forces you to apply a clear structure to these ideas. This structure can help you generate both a higher quantity of ideas as well as a higher quality of ideas.
When do I need to be MECE in a consulting case interview?
In a case interview, there are several key sections where applying the MECE principle is crucial:
1. Case Opening and Problem Clarification
At the beginning of the case interview, when you're given the prompt, it's essential to clarify the problem. Ensure that you understand the problem statement clearly. If the problem is complex or multifaceted, use the MECE principle to break down the problem into a few smaller, more manageable problems.
2. Framework Development
This is where the MECE principle is most commonly used. When you're asked to structure your approach to solving the case, you need to devise a framework that is both mutually exclusive and collectively exhaustive. This means creating a clear and comprehensive breakdown of the problem into distinct categories.
3. Data Gathering
As you begin to collect information and data, it's important to maintain a MECE structure. Ensure that the data you're gathering fits into the defined categories of your framework.
4. Analysis and Problem-Solving
Throughout the case interview, as you analyze the information you've gathered, apply the MECE principle to maintain a structured approach. Make sure that your analysis remains clear, distinct, and that you're not overlapping or omitting any relevant factors.
5. Hypothesis Testing
If you need to make assumptions or hypotheses during the case, ensure that they align with your MECE framework. This helps in maintaining a structured and focused approach to problem-solving.
6. Recommendations and Conclusion
When you reach the stage of providing recommendations or conclusions, it's crucial to ensure that your proposed solutions or suggestions are consistent with the MECE framework you've established. This demonstrates that your recommendations are well-considered and comprehensive.
Remember, the MECE principle is not just a framework for structuring your approach; it's a way of thinking that permeates every stage of the case interview. It helps you maintain clarity, organization, and effectiveness in your problem-solving process.
By consistently applying MECE, you demonstrate your ability to approach complex problems in a structured and logical manner, a highly valued skill in consulting.
How can I make consulting case interview frameworks MECE?
There are five different strategies you can use to make frameworks MECE:
- Two-Part MECE Frameworks
- MECE Math Frameworks
- Including “Other” to Make MECE
- Breaking Down Processes
- Breaking Down Stakeholders
Two-Part MECE Frameworks
The simplest way to make your framework MECE is to use a two-part framework that follows the structure of “X” and “Not X.”
For example, the following pairs of words are all MECE frameworks.
These frameworks are mutually exclusive because there is no overlap between “X” and “Not X.” Additionally, these frameworks are also collectively exhaustive because all ideas and possibilities must be either “X” or “Not X” by definition.
These two-part MECE frameworks are simple and quick to develop. This MECE strategy is most commonly used when trying to brainstorm a long list of ideas.
For example, if you are brainstorming barriers to entry in a market, you could use this MECE strategy to develop the following framework.
This strategy guarantees that your framework is MECE.
MECE Math Frameworks
Using math formulas are also a quick way to develop MECE frameworks. This MECE strategy is most commonly used when trying to identify ways to improve a particular metric.
For example, if you are trying to identify how to increase profits for a company, you could use this MECE strategy.
We know the following basic formulas on profit:
- Profit = Revenue – Costs
- Revenue = Quantity * Price
- Costs = Variable Costs + Fixed Costs
Therefore, your MECE framework could look like the following.
All of the different parts of this framework are mutually exclusive because each part makes up the formula for profit. Additionally, this framework is collectively exhaustive because it includes all of the different terms in the profit formula.
Including “Other” to Make MECE
Sometimes, it can be difficult to brainstorm all ideas or possibilities that are collectively exhaustive. In these cases, focus on identifying the largest and most relevant parts of the whole and then add “Other” into your framework to make it collectively exhaustive.
For example, let’s say that you are trying to brainstorm all of the different products and services that Apple sells.
You may brainstorm the following different Apple products and services:
This list is likely not collectively exhaustive because we are probably missing a few smaller products or services that Apple sells.
To make this list collectively exhaustive, we can add “Other” to it.
The rationale is that as long as we have listed the major products and services, the smaller products and services that make up a small percentage of total revenues can be grouped into “Other.”
You should not use this strategy too much, but it is an easy way to make your framework more MECE if you are struggling with developing a MECE structure.
Breaking Down Processes
When dealing with business situations that involve improving processes, an easy way to create a MECE framework is to break the process down into separate, distinct components.
This approach can help you systematically go through each component to identify issues or opportunities for improvement.
For example, let’s say that you are trying to determine how to improve how Amazon fulfills orders to customers in order to decrease delivery time. You can decompose this process into the following components:
- Take the customer order information from the website
- Determine the right warehouses to ship from
- Select and package the right products
- Ship the products to large distribution centers
- Determine which local delivery vehicle and route the products should be transported in
- Deliver the products to the customer’s doorstep
This MECE framework ensures that you are not missing any steps in the process and that you are not assessing the same step twice.
Breaking Down Stakeholders
When dealing with business situations that involve many different stakeholders, an easy way to create a MECE framework is to identify all of the major groups of stakeholders.
This approach can help you systematically go through each stakeholder to identify strategies to target each group.
For example, let’s say that you are working with a real estate developer that is trying to get approval to build a new port in the city to facilitate the transportation of goods.
In order to develop a strategy to get approval, you can identify the major stakeholders involved:
- City government officials
- Shipping companies
- Labor unions
- Financial institutions
- Environmental groups
This MECE framework ensures that you cover the major stakeholder groups and that you do not mix different stakeholder groups together.
Do I always need to be 100% MECE?
There are many different case interviews and business situations in which creating a MECE framework is incredibly difficult.
For example, how would you create MECE frameworks for the following?
- Deciding whether to enter a market
- Deciding whether to launch a new product
- Deciding whether to acquire a company
You can read our article on case interview frameworks to learn how to create robust and tailored frameworks for each of these cases.
In short, during case interviews, it is unreasonable to expect anyone to create 100% mutually exclusive, collectively exhaustive frameworks to every case or question. In interviews, you are under a lot of pressure and likely only have a few minutes to develop a framework.
Even McKinsey, BCG, and Bain consultants would likely not be able to create a framework that is 100% MECE even if they were given days to develop one.
Rest assured that as long as your framework is 80% MECE or more, it is likely a far better framework than most interview candidates.
Therefore, focus on these three points when making MECE frameworks.
1. Check that you are being mutually exclusive: It is easier to be mutually exclusive than to be collectively exhaustive. Therefore, do a quick check to make sure that none of the areas in your framework have significant overlap.
2. Focus on the biggest and most important areas: Generating a collectively exhaustive list of ideas can be difficult. In these situations, focus on including areas that collectively make up 80% or more of the whole. You can categorize and group everything else as “Other” and justify this by saying that the other areas are much smaller and less relevant than the major areas you have identified.
3. Ensure your framework areas are highly relevant: It is better to have a non-MECE framework in which every area is highly relevant to the case than to have a MECE framework in which no area is relevant to the case. Your framework can be 100% MECE, but if it is inappropriate for the case or business situation, it is useless.
What are tips for being MECE?
When trying to be MECE, make sure to follow the tips below. These will help make your thinking and framework more comprehensive, clear, and efficient.
MECE tip #1: Order your thinking logically
Whenever possible, try to organize your thinking in a logical order.
For example, if you are analyzing an issue and segmenting it by timeframe, arrange your thoughts in order of short-term, medium-term, and long-term. This is a logical order that is arranged by length of time.
It does not make sense to order your thinking by long-term, short-term, and medium-term. This ordering is confusing and harder to follow.
MECE tip #2: Have three to five elements
Your thinking needs to be both comprehensive, but also clear and easy to follow. Therefore, your framework should have at least three elements to be able to cover enough breadth of the key issue or problem.
Additionally, your framework should have no more than five elements. Any more than this will make your framework too complicated and difficult to follow. By having more than five branches, you also increase the likelihood that there will be redundancies or overlap among your elements, which is not ideal.
Having three to five elements helps achieve a balance between going deep into specific sub-issues and covering a broad range of aspects. It balances breadth and depth.
MECE tip #3: Branches should be parallel
The elements in your framework should all be on the same logical level.
For example, if you decide to segment your thinking by geography, your elements could be: North America, South America, Europe, Asia, Africa, Australia, and Antarctica. This segmentation is logical because each segment is a continent.
It would not make sense to segment by United States, South America, China, India, Australia, and rest of the world. This segmentation does not follow logical consistency because it mixes continents and countries.
Nail Your Consulting Case Interviews
Here are the resources we recommend to learn the most robust, effective case interview strategies in the least time-consuming way:
- Comprehensive Case Interview Course (our #1 recommendation): The only resource you need. Whether you have no business background, rusty math skills, or are short on time, this step-by-step course will transform you into a top 1% caser that lands multiple consulting offers.
- Hacking the Case Interview Book (available on Amazon): Perfect for beginners that are short on time. Transform yourself from a stressed-out case interview newbie to a confident intermediate in under a week. Some readers finish this book in a day and can already tackle tough cases.
- The Ultimate Case Interview Workbook (available on Amazon): Perfect for intermediates struggling with frameworks, case math, or generating business insights. No need to find a case partner – these drills, practice problems, and full-length cases can all be done by yourself.
- Case Interview Coaching: Personalized, one-on-one coaching with former consulting interviewers
- Behavioral & Fit Interview Course: Be prepared for 98% of behavioral and fit questions in just a few hours. We'll teach you exactly how to draft answers that will impress your interviewer
- Resume Review & Editing: Transform your resume into one that will get you multiple interviews