The gist of it:

The door test is used to distinguish between decisions that are difficult to reverse or have long-lasting consequences (one-way door) and those that can be easily reversed or corrected (two-way door).

One-way door decisions need to be made carefully whereas two-way door decisions can be made quickly or automated using rules.

How to use it:

When faced with any decision, first decide if it is a one-way door or two-way door decision.

One-Way Door Decisions:

• These are significant, high-impact choices that are difficult to reverse.

• They involve substantial commitments of resources, time, and effort.

• It is therefore important to make time for careful consideration, data analysis, and thorough evaluation before making one-way door decisions.

• Once you've gone through a one-way door, it's hard to turn back, and the effects are long-lasting.

• Examples include: Choosing a college major, getting married, purchasing a home, relocating for work.

Two-Way Door Decisions:

• These are choices that can be easily reversed or undone.

• They are lower-risk decisions that allow for experimentation and learning.

• These decisions should be made as quickly and efficiently as possible.

• If a two-way door decision turns out to be the wrong choice, you can easily reverse it without significant consequences.

• Examples include trying a new brand of shampoo, changing your workout routine, choosing a new route to go to work, taking a friend’s recommendation to try a new restaurant.

Deep Dive

Jeff Bezos, one of the world's most renowned business leaders, is often celebrated not just for his entrepreneurial acumen but also for his exceptional ability as a thinker and innovator. His remarkable success in building Amazon into a global e-commerce and technology giant is a testament to his strategic vision and pioneering mindset.

But arguably his chief skill is the ability to make a number of smart decisions and make them as quickly as possible. As Bezos wrote in a shareholder letter:

Some decisions are consequential and irreversible or nearly irreversible -- one-way doors -- and these decisions must be made methodically, carefully, slowly, with great deliberation and consultation. If you walk through and don't like what you see on the other side, you can't get back to where you were before. We can call these Type 1 decisions.

But most decisions aren't like that -- they are changeable, reversible -- they're two-way doors. If you've made a sub-optimal Type 2 decision, you don't have to live with the consequences for that long. You can reopen the door and go back through. Type 2 decisions can and should be made quickly by high judgment individuals or small groups.

Many of us place equal value on almost every decision, typically for the fear of being wrong. But sometimes it is fine being wrong - or at the very least you don’t have to worry about being wrong because these decisions can be reversed relatively quickly.

For every decision you make, the first thing to do is decide if this is a one-way door or two-way door decision

One-way door decisions are almost impossible to reverse - Think selling your company or quitting your job. In short, figuratively jumping off a cliff. Once you make this decision, there’s no going back.

Two-way door decisions are easy to reverse. Think website design changes, pricing strategy experiments, changing your hair colour, trying a new brand of milk.

It’s easy to mistake two-way door decisions for one-way door ones - letting fear and caution paralyse you and make no decision at all.

The “So What”

Make as many two-way door decisions as you can, as efficiently as you can.

Some of them you will get wrong. And that’s totally fine because you can unwind them quickly. But slowly and surely, you will get more experienced and learn how to make better decisions.

And that will mean that over time, more of your two-way door decisions will work out and you would have gained all the skills, knowledge and experience that comes along with it.

Sources:
Amazon Founder Jeff Bezos: This Is How Successful People Make Such Smart Decisions
One-way & Two-way Door Decisions