During my undergrad and early grad school years, I flirted with the idea of working for a management consulting firm (e.g. McKinsey, Bain, BCG, Monitor, etc). At the time, it seemed the top students were trying to get into those places, so it seemed like the thing to do.
During the interviews with these firms, they would often ask very big questions like: “Estimate the number of tires sold yearly worldwide.” They would expect you to come up with plausible estimates. They did not care if you got the estimate right. They wanted to watch you reason through a tough problem where you have very little understanding.
One key to reasoning through these kinds of questions is to ensure that your logic is “mutually exclusive and collectively exhaustive (MECE)” at each step. The MECE principle is vital in electrical engineering and computer science programs. It is an important concept for problem solvers to understand.
- Mutually exclusive means that as you break the problem down the sub pieces do not have overlap. The sub pieces need to be mutually exclusive otherwise you may double count some of the data.
- Collective exhaustive means that as you break the problem down that you need to have full coverage of the entire range of the problem. Otherwise you may not count some of the data.
It is often helpful in brainstorming, negotiation, and decision-making processes to ask yourself if you have been mutually exclusive and collectively exhaustive in your analysis.
What are your thoughts on MECE?