Decisions
5 min

One-way and two-way doors

Classify the decision by whether it can be undone cheaply, and size the process to that answer rather than to how important it feels.

Time cost
5 min
Output
A classification and a matching process budget.
Steps
6

Use when

  • Before any other method. It decides how much method the decision deserves.
  • A decision is being over-processed, or a serious one is being made casually.
  • You are delegating and need to say how much care is warranted.

Do not use when

  • Reversibility is genuinely unknown — find that out first, because it is the input.
  • The decision is reversible but the reversal has a high fixed cost, which makes it a third category worth naming.

Inputs required

  • The decision
  • An honest estimate of the cost of reversing it

Procedure

  1. 01

    Ask what reversal costs

    Not whether reversal is theoretically possible — almost everything is. What would it cost in money, time and standing to walk it back in six months?

  2. 02

    Classify

    Two-way door: reversal is cheap. One-way: reversal is impossible or ruinous. Costly-to-reverse: possible but expensive, which is the category most decisions actually fall into.

  3. 03

    Two-way door — decide now

    Delegate it to whoever is closest to the information. Set a review date. The cost of deciding slowly exceeds the cost of deciding wrongly.

  4. 04

    One-way door — slow down deliberately

    Widen the options, run a premortem, get outside input, write the reasoning down. This is where process earns its cost.

  5. 05

    Costly-to-reverse — buy an option

    Look for a way to convert it into a two-way door: a trial, a break clause, a staged commitment. That conversion is usually cheaper than either the process or the mistake.

  6. 06

    Say the classification out loud

    Most of the value is in the group agreeing which type this is. Disagreement about the type is usually the real disagreement.

Characteristic failure mode

Door inflation. As people become more senior or more cautious, two-way doors get treated as one-way, and an organisation or a household becomes systematically slow at decisions whose mistakes cost almost nothing.

Worked example

A team is in its third week of deciding which project-tracking tool to use.

  1. 01Cost of reversal: a data export and roughly two days of migration.
  2. 02Classification: two-way door.
  3. 03Assigned to one person with a decision deadline of Friday and a review in three months.

Result

Three weeks of process on a two-day mistake. The classification took four minutes and was the entire decision.

Where to go next

Also cited by
Regret minimisation