The MECE principle, pronounced 'me see', mutually exclusive and collectively exhaustive, is a grouping principle for separating a set of items into subsets, the choice of subsets should be mutually exclusive and collectively exhaustive.
The MECE principle is useful in the business mapping process where the optimum arrangement of information is exhaustive and does not double count at any level of the hierarchy.
Examples of MECE arrangements include categorizing people by year of birth (assuming all years are known). A non-MECE example would be categorization by nationality, because nationalities are neither mutually exclusive (some people have dual nationality) nor collectively exhaustive (some people have none).
The McKinsey Way 
See also 
- Spencer, Tom. "MECE Framework".
- Rasiel, Ethan (February 1, 1999). The McKinsey Way (1 ed.). McGraw-Hill. ISBN 978-0-07-053448-3.
- Rasiel, Ethan; Friga, Paul (September 26, 2001). The McKinsey Mind: Understanding and Implementing the Problem-Solving Tools and Management Techniques of the World's Top Strategic Consulting Firm (1 ed.). McGraw-Hill. ISBN 978-0-07-137429-3.
- Friga, Paul (November 24, 2008). The McKinsey Engagement: A Powerful Toolkit For More Efficient and Effective Team Problem Solving (1 ed.). McGraw-Hill. ISBN 978-0-07-149741-1.