# What does MECE mean? > **MECE:** MECE (mutually exclusive, collectively exhaustive) is a rule for splitting a topic into parts that do not overlap and that together cover the whole. - Source: https://ai-presentations.com/glossary/mece/ - Updated: 21 October 2026 - Language: English - German version: https://ai-presentations.com/de/glossar/mece/ Also called: mutually exclusive collectively exhaustive, MECE principle, MECE framework **MECE** stands for *mutually exclusive, collectively exhaustive*. You split a topic into parts so that: - **mutually exclusive**: no item belongs to two parts at once, and - **collectively exhaustive**: every item belongs to some part, nothing is left over. It is a basic rule of structuring in consulting because it protects an analysis from two common errors: counting the same thing twice, and missing a part of the problem entirely. ## A simple example Say you want to explain why profit fell. A MECE split is **revenue** and **costs**: every change in profit comes from one or the other, and no euro sits in both. Go one level down and revenue splits into **volume** and **price**, costs into **fixed** and **variable**. Each level is again complete and free of overlap. > **Avoid: Not MECE** > > **Why profit fell:** higher costs, weak sales in Germany, the new competitor, lower prices. > > “Weak sales” and “lower prices” overlap, the competitor may be the cause of both, and nothing covers sales outside Germany. > **Do: MECE** > > **Why profit fell:** revenue fell by €2.1m (volume −€1.4m, price −€0.7m) and costs rose by €0.9m (energy +€0.6m, wages +€0.3m). > > Every euro of the change sits in exactly one box, and the boxes add up to the total. ## How to make a breakdown MECE 1. **Pick one dimension per level.** Split by region, or by product, or by customer type, but not by two at once. 2. **Check the sum.** If the parts are numbers, they must add up to the total. If they do not, something overlaps or is missing. 3. **Add “other” only when it is small.** A large “other” bucket means the split is not exhaustive yet. 4. **Test with an item.** Take any real customer, cost line or idea and see whether it fits exactly one box. ## MECE on slides MECE thinking shows up in presentations as [issue trees](https://ai-presentations.com/glossary/issue-tree/), [driver trees](https://ai-presentations.com/glossary/driver-tree/), [waterfall charts](https://ai-presentations.com/glossary/waterfall-chart/) and [two-by-two matrices](https://ai-presentations.com/glossary/two-by-two-matrix/). A waterfall chart, for example, is MECE by construction: the drivers between the start and end value must add up, or the chart does not close. *A bridge only closes when the drivers are mutually exclusive and add up to the change. Example with fictional figures.* 5. Margin expansion came mostly from volume and better network utilization Pair MECE groupings with [action titles](https://ai-presentations.com/guides/action-titles/): the title states the conclusion, and the MECE structure on the slide shows that nothing was left out. ## Frequently asked questions ### How do you pronounce MECE? Most people say “mee-see”. Some say each letter, M-E-C-E. Both are understood in consulting. ### Where does MECE come from? The term is usually traced to Barbara Minto, who used it at McKinsey in the late 1960s as part of what became the pyramid principle. ### Does every list in a presentation have to be MECE? No. MECE matters when you break down a problem, a number or a set of options, because gaps and overlaps there lead to wrong conclusions. A list of examples or highlights does not need to be exhaustive. ## Related pages - [Pyramid principle](https://ai-presentations.com/guides/pyramid-principle/): The pyramid principle by Barbara Minto: give the answer first, group the support and order it. With a worked example and an outline you can reuse for a deck. - [Action titles](https://ai-presentations.com/guides/action-titles/): Write slide headlines as full sentences. Six rules for action titles, twelve before-and-after examples and a quick test you can run on any deck. - [Issue tree](https://ai-presentations.com/glossary/issue-tree/): An issue tree splits one key question into sub-questions, branch by branch, so every part can be analyzed and nothing is missed. Includes a worked example. - [Driver tree](https://ai-presentations.com/glossary/driver-tree/): A driver tree breaks a metric such as revenue or profit into the measurable drivers behind it, linked by simple math. See a worked example you can copy. --- ai-presentations.com is published by Slaide (https://www.slaide.de), a sole proprietorship run by Nathalie Scholl in Heilbronn, Germany. [How this site is written, checked and corrected](https://ai-presentations.com/editorial-policy/).