TRIZ Inversion (Principle #13)

Overview

Inversion is one of Genrich Altshuller's 40 Inventive Principles from TRIZ (Theory of Inventive Problem Solving), derived from analysis of over 200,000 patents. The principle states: reverse or invert the action used to solve the problem, or make stationary parts movable and movable parts stationary.

Inversion appears in three forms:

1. •Action Inversion - Do the opposite of the expected action
2. •Property Inversion - Reverse the property (hot to cold, push to pull)
3. •Perspective Inversion - Turn the object or viewpoint upside down

The underlying insight: when conventional approaches fail, the solution often lies in doing the exact opposite. What seems counterintuitive frequently unlocks breakthrough innovations.

When to Use

• •Conventional solution attempts have reached diminishing returns
• •The standard approach creates unintended negative consequences
• •Physical constraints prevent the obvious solution
• •You need to break mental fixation on a single approach
• •The problem involves getting something out of a tight space
• •Heat, force, or pressure applied normally doesn't work
• •You need to question fundamental assumptions about how things "should" work

The Process

Step 1: Identify the Conventional Action

What is the standard, expected, or obvious way to solve this problem?

Example: To loosen stuck metal parts, heat the outer part to expand it.

Step 2: Invert the Action, Property, or Perspective

Ask: what if I did the exact opposite?

• •Action Inversion: Instead of heating, try cooling
• •Property Inversion: Instead of expanding, try contracting
• •Perspective Inversion: Instead of working from outside-in, try inside-out

Example: Cool the inner part instead of heating the outer part.

Step 3: Analyze Why the Inversion Works

Understand the physics, psychology, or logic of why the opposite approach succeeds.

Example: Cooling the inner part causes it to contract, creating clearance for removal.

Step 4: Test Edge Cases

Verify that the inverted solution works across expected scenarios and doesn't create new problems.

Example: Ensure cooling method doesn't damage materials or create condensation issues.

Step 5: Generalize the Inversion Pattern

Document the insight for future applications in similar contexts.

Example: "When expansion doesn't work, try contraction" becomes a reusable heuristic.

Example Application

Situation (Manufacturing Defect): Paint spray booth generates overspray waste that contaminates products and clogs filters.

Application:

1. •Conventional Action: Move paint toward the object
2. •Inversion: Make the object move to capture paint (electrostatic painting)
3. •Why It Works: Charged object attracts paint particles, reducing overspray by 30-40%
4. •Edge Cases: Requires conductive objects, managed humidity levels
5. •Pattern: "Instead of pushing substance toward target, make target pull substance"

Outcome: Reduced paint waste by 35%, improved finish quality, lower filter replacement costs.

Anti-Patterns

• •Inverting without understanding why the original approach failed
• •Applying inversion mechanically without considering context
• •Ignoring safety implications of reversed actions (cooling with liquid nitrogen without ventilation)
• •Assuming all problems have an inverted solution
• •Over-complicating simple problems that don't need inversion
• •Failing to test whether inversion actually improves the outcome

Related

• •triz-asymmetry (break symmetry rather than maintain it)
• •triz-taking-out (extract rather than add)
• •reversal-method (de Bono's lateral thinking technique)
• •first-principles-thinking (question assumptions before inverting)
• •pre-mortem (invert success planning into failure analysis)