1. Tame problem: is clear and repeatable. Can be solved efficiently with an engineered solution. Once you figure out the model for solving the "well behaved" problem, it works every-time. (Discrete function)

2. Business problem: is clear and repeatable ... but it is not obvious what to do about it. Can be solved by discovering what makes the problem smaller and/or makes the solution better. Once you figure out the model for continuously incorporating those improvements the problem is solved. (Continuous function)

3. Analytic problem: is an open ended issue that does not have a clear path to success. Can be solved by using a questioning technique that quantifies what you are trying to accomplish. Once you figure out the model for quantifying the problem (gives you a metric for how close you are to a goal), it can be solved with measurable goals.

4. Wicked problem*: chaotic, not well understood, and you only get one chance to solve it. You are facing a wicked problem when you: 1) don't know if you did the right thing until it is too late; and 2) the problem can't be repeated or revisited.

*term coined by two professors at University of California, Berkeley Horst Rittel and Melvin Webber

The three step approach to solving a wicked problem is:

FIRST: Begin with either a desired conclusion (engineering methodology) or a curiosity (design thinking methodology) about a wicked problem

THEN: use a simulation Toolkit that allows you to sneak up on future problems with an iterative solution prototype that allows you to simulate all possible scenarios*. Iterate/optimize the designed prototype until the solution works correctly in all scenarios.

FINALLY: Once you have a model for solving the simulated problem can be solved by applying the prototyped solution.

*Simulate all scenarios, even the unlikely ones, so that real life people don't get hurt while learning. Don't allow bias to limit what you simulate for. "just because it is crazy doesn't mean it isn't true"