I smell a RAT, or why you’re doing MVPs wrong.

Jon Harmer
5 min readJun 21, 2023
Photo by Matt Seymour on Unsplash

In the world of startups and product development, the concept of the Minimum Viable Product (MVP) has gained significant popularity. It is an approach that focuses on creating a product with the bare minimum features to gather feedback and validate assumptions. Lots of people get hung up on what this MVP is “supposed to be.” They get hung up on the idea that an MVP is a finished product, or that it should be a certain way. Like the discussion around the classic MVP car analogy from Henrik Kniberg:

Henrik’s original image

expressed by this recent twitter thread version

People who criticize the car analogy get hung up on the “no one will buy a skateboard if they need a car” part of it, and miss the point. The point of an MVP is to learn as much as possible about your customers and their needs. The point of the metaphor is that an MVP isn’t about slowly building out your final product in stages (the top line where you start with 1 car wheel) but rather that you need to figure out what the underlying need is (to get from A to B faster, as in the classic Henry Ford quote).

But rather than get hung up on what an MVP is “supposed to be” or whether or not Henrik’s graphic is perfect or not, we should instead focus on what MVPs can do for you. They’re supposed to be learning tools. Eric Ries calls the MVP the “version of a new product which allows a team to collect the maximum amount of validated learning about customers with the least effort.”

“Validated learning about customers” is the key element there. So instead of getting all wrapped up in what is or isn’t “an MVP,” let’s focus on learning. And the thing I think most companies need to learn more about quickly and early is their assumptions. This is where the concept of Riskiest Assumption Tests (RATs) comes into play, offering a better way of…



Jon Harmer

I understand users and buyers and their problems. I help solve those problems and communicate that value.