Substitute

Ask: what component, material, person, process, or rule could be swapped for something different?

Why it works

Substitution forces the thinker to identify which elements of a system they are treating as fixed that are actually variable. Most design failures and missed innovations come from the invisible assumption that a particular element must stay as it is. Naming potential substitutes — even implausible ones — surfaces those hidden assumptions and opens the design space.

How to do it

1. List the key components of your product, process, or problem.
2. For each component, ask: "What else could do this job? What if we used a different material, person, or rule?"
3. Include obviously implausible substitutes — they sometimes point to the real solution obliquely.
4. Record all substitutes before evaluating any.

Evidence

Divergent thinking research supports constraint relaxation — making implicit assumptions explicit — as a driver of creative ideas. SCAMPER operationalizes this for the Substitute dimension. The checklist approach as a whole is practitioner consensus. (mechanistic)

SCAMPER generates ideas but does not evaluate them; quality filtering requires separate domain judgment that the technique does not provide.

Common mistake

Substituting only within the obvious category (replacing one material with a similar material) rather than across categories — "what if a person did what this software does?" is a richer substitution.