MECEE

10 August 2004

I read a bit. One book I that had some interesting ideas was The McKinsey way by Ethan M. Rasiel. Many of the ideas are not new, the 8020 rule, and elevator pitch, and so on, but it does talk about the need to be MECE (pronounced ‘me-se’) in writing and thinking.

That is to say, every plan, presentation, or even memo must be present their ideas in a mutually exclusive, collectively exhaustive manner. The book puts it this way:

One of the most fundamental tenants of McKinsey problem solving is the concept of MECE, mutually exclusive, collectively exhaustive. MECE can be used when developing and listing issues related to the problem at hand. First, the associate must ensure that the list is

Then, she must check that it is collectively exhaustive, that it includes every issue relevant to the problem. This approach prevents overlap and confusion. A “major issues list” should contain no less than two, and no more than five issues, with three being the ideal number. The consultant must make a concerted effort to fit each business problem faced by the company or non-profit under one of the 2–5 issues on the major issues list. If this fails, there is always the option of creating a category of “other issues”, although this is most effective when utilized as a sub-heading for presentation purposes.

Everyone at McKinsey gets well drilled in the art of being MECE:

MECE structures your thinking with maximum clarity–when you think you have determined the issues, take a hard look at them. Is each one a separate and distinct issue? If so, then your issue list is mutually exclusive. Does every aspect of the problem come under one (and only one) of these issues? If so, then your issues are collectively exhaustive … [so that] every document (including internal memos), every presentation, every e-mail and voice mail produced by McKinsey-ite is supposed to be MECE.

This is closely related to the pyramid method described by Barbara Minto in her book The Minto Pyramid Principle: Logic in Writing, Thinking, & Problem Solving.

The ideas behind the pyramid method and MECE are used a lot by the big consulting firms (McKinsey has already been mentioned, but BC, Anderson/Accenture). They are also used by strategy case competition teams, and even by students writing theses.

Here is a fragment (well 150k) of a presentation from the Harvard Business School that shows some of these ideas. It is also a good example of how to tackle cases in general.