Critically Important Assumptions

Assumptions whose failure would materially change a plan or make it unworkable. The practice is to state these dependencies explicitly, investigate consequential uncertainties early, and let the results affect the next commitment. How many assumptions matter and which should be tested first depend on the particular decision.

A critical assumption is a proposition that must be sufficiently true for a plan to make sense. It differs from a general concern: you can state what depends on it and how the decision would change if it were false. For a delivery service, sufficient demand, workable delivery times, and an affordable operating cost may each be essential even if the branding is excellent.

Prioritize assumptions by their consequences, uncertainty, and how feasibly they can be investigated. The easiest thing to measure is not necessarily the most useful thing to learn. A good early test addresses a consequential uncertainty before a commitment becomes difficult to reverse. Tests can narrow uncertainty rather than producing a permanent yes-or-no verdict.

When to use it

Before committing to a venture, course, move, recurring arrangement, or other plan that depends on uncertain conditions.

How it can help

Makes the conditions behind a plan explicit and directs early inquiry toward uncertainties that could change a costly or difficult-to-reverse commitment.