Oh MECE tree, Oh MECE tree...

Okay, so I'm a few days late for the joke.

The MECE tree is a favorite of consultants, and is also a great tool for making decisions as an engineer. A MECE tree is simply a decision tree that is Mutually Exclusive and Completely Exhaustive.

Let's look at an example:

The first step to solving the issue is to list broad categories of solutions - there should be no possible solution that isn't covered by these categories (mutually exclusive), or that fits into multiple categories (completely exhaustive).

Then, for each broad category of solutions, narrow it down further. These should be concrete action items. At the end, analyze each action item for its feasibility.

This is one of those tools that seems obvious when looking at an electric bill that's too high, but for complex problems this can require a lot of brainpower. I've found this to be a fun team activity - throwing out random solutions to problems too often results in missing one (or two, or ten). This is a tested way to structure problem-solving, enjoy!