40 Inventive Principles With Examples

This format for the 40 Inventive Principles and the accompanying examples was developed by Karen Tate and Ellen Domb for their class, "Practical Innovation." which was the subject of the article "How to Help TRIZ Beginners Succeed") in the April, 1997 issue of the TRIZ Journal. Readers have permission to download single copies for personal study.

Principle 1. Segmentation

  1. Divide an object into independent parts.

  2. Make an object easy to disassemble.

  3. Increase the degree of fragmentation or segmentation.

Principle 2. Taking out

  1. Separate an interfering part or property from an object, or single out the only necessary part (or property) of an object.

Principle 3. Local quality

  1. Change an object's structure from uniform to non-uniform, change an external environment (or external influence) from uniform to non-uniform.

  2. Make each part of an object function in conditions most suitable for its operation.

    (Part C continued on the next page.)

  3. Make each part of an object fulfill a different and useful function.

Principle 4. Asymmetry

  1. A. Change the shape of an object from symmetrical to asymmetrical.

  2. If an object is asymmetrical, increase its degree of asymmetry.

Principle 5. Merging

  1. Bring closer together (or merge) identical or similar objects, assemble identical or similar parts to perform parallel operations.

  2. Make operations contiguous or parallel; bring them together in time.

Principle 6. Universality

  1. Make a part or object perform multiple functions; eliminate the need for other parts.

Principle 7. "Nested doll"

  1. Place one object inside another; place each object, in turn, inside the other.

  2. Make one part pass through a cavity in the other.

Principle 8. Anti-weight

  1. To compensate for the weight of an object, merge it with other objects that provide lift.

  2. To compensate for the weight of an object, make it interact with the environment (e.g. use aerodynamic, hydrodynamic, buoyancy and other forces).

Principle 9. Preliminary anti-action

  1. If it will be necessary to do an action with both harmful and useful effects, this action should be replaced with anti-actions to control harmful effects.

  2. Create beforehand stresses in an object that will oppose known undesirable working stresses later on.

Principle 10. Preliminary action

  1. Perform, before it is needed, the required change of an object (either fully or partially).

  2. Pre-arrange objects such that they can come into action from the most convenient place and without losing time for their delivery.

Principle 11. Beforehand cushioning

  1. Prepare emergency means beforehand to compensate for the relatively low reliability of an object.

Principle 12. Equipotentiality

  1. In a potential field, limit position changes (e.g. change operating conditions to eliminate the need to raise or lower objects in a gravity field).

Principle 13. 'The other way round'

  1. Invert the action(s) used to solve the problem (e.g. instead of cooling an object, heat it).

    (Part B continued on the next page.)

  2. Make movable parts (or the external environment) fixed, and fixed parts movable).

  3. Turn the object (or process) 'upside down'.

Principle 14. Spheroidality - Curvature

  1. Instead of using rectilinear parts, surfaces, or forms, use curvilinear ones; move from flat surfaces to spherical ones; from parts shaped as a cube (parallelepiped) to ball-shaped structures.

  2. Use rollers, balls, spirals, domes.

  3. Go from linear to rotary motion, use centrifugal forces.

Principle 15. Dynamics

  1. Allow (or design) the characteristics of an object, external environment, or process to change to be optimal or to find an optimal operating condition.

    (Part B continued on the next page.)

  2. Divide an object into parts capable of movement relative to each other.

  3. If an object (or process) is rigid or inflexible, make it movable or adaptive.

Principle 16. Partial or excessive actions

  1. If 100 percent of an object is hard to achieve using a given solution method then, by using 'slightly less' or 'slightly more' of the same method, the problem may be considerably easier to solve.

Principle 17. Another dimension

  1. To move an object in two- or three-dimensional space.

  2. Use a multi-story arrangement of objects instead of a single-story arrangement.

  3. Tilt or re-orient the object, lay it on its side.

  4. Use 'another side' of a given area.

Principle 18. Mechanical vibration

  1. Cause an object to oscillate or vibrate.

  2. Increase its frequency (even up to the ultrasonic).

  3. Use an object's resonant frequency.

  4. Use piezoelectric vibrators instead of mechanical ones.

  5. Use combined ultrasonic and electromagnetic field oscillations.

Principle 19. Periodic action

  1. Instead of continuous action, use periodic or pulsating actions.

  2. If an action is already periodic, change the periodic magnitude or frequency.

  3. Use pauses between impulses to perform a different action.

Principle 20. Continuity of useful action

  1. Carry on work continuously; make all prts of an object work at full load, all the time.

  2. Eliminate all idle or intermittent actions or work.

Principle 21. Skipping

  1. Conduct a process , or certain stages (e.g. destructible, harmful or hazardous operations) at high speed.

Principle 22. "Blessing in disguise" or "Turn Lemons into Lemonade"

  1. Use harmful factors (particularly, harmful effects of the environment or surroundings) to achieve a positive effect.

  2. Eliminate the primary harmful action by adding it to another harmful action to resolve the problem.

    Amplify a harmful factor to such a degree that it is no longer harmful.

Principle 23. Feedback

  1. Introduce feedback (referring back, cross-checking) to improve a process or action.

  2. If feedback is already used, change its magnitude or influence.

Principle 24. 'Intermediary'

  1. Use an intermediary carrier article or intermediary process.

  2. Merge one object temporarily with another (which can be easily removed).

Principle 25. Self-service

  1. Make an object serve itself by performing auxiliary helpful functions

  2. Use waste resources, energy, or substances.

Principle 26. Copying

  1. Instead of an unavailable, expensive, fragile object, use simpler and inexpensive copies.

  2. Replace an object, or process with optical copies.

  3. If visible optical copies are already used, move to infrared or ultraviolet copies.

Principle 27. Cheap short-living objects

  1. Replace an inexpensive object with a multiple of inexpensive objects, comprising certain qualities (such as service life, for instance).

Principle 28 Mechanics substitution

  1. Replace a mechanical means with a sensory (optical, acoustic, taste or smell) means.

  2. Use electric, magnetic and electromagnetic fields to interact with the object.

  3. Change from static to movable fields, from unstructured fields to those having structure.

  4. Use fields in conjunction with field-activated (e.g. ferromagnetic) particles.

Principle 29. Pneumatics and hydraulics

  1. Use gas and liquid parts of an object instead of solid parts (e.g. inflatable, filled with liquids, air cushion, hydrostatic, hydro-reactive).

Principle 30. Flexible shells and thin films

  1. Use flexible shells and thin films instead of three dimensional structures

  2. Isolate the object from the external environment using flexible shells and thin films.

Principle 31. Porous materials

  1. Make an object porous or add porous elements (inserts, coatings, etc.).

  2. If an object is already porous, use the pores to introduce a useful substance or function.

Principle 32. Color changes

  1. Change the color of an object or its external environment.

  2. Change the transparency of an object or its external environment.

Principle 33. Homogeneity

  1. Make objects interacting with a given object of the same material (or material with identical properties).

Principle 34. Discarding and recovering

  1. Make portions of an object that have fulfilled their functions go away (discard by dissolving, evaporating, etc.) or modify these directly during operation.

  2. Conversely, restore consumable parts of an object directly in operation.

Principle 35. Parameter changes

  1. A. Change an object's physical state (e.g. to a gas, liquid, or solid.

  2. Change the concentration or consistency.

  3. Change the degree of flexibility.

  4. Change the temperature.

Principle 36. Phase transitions

  1. Use phenomena occurring during phase transitions (e.g. volume changes, loss or absorption of heat, etc.).

Principle 37. Thermal expansion

  1. Use thermal expansion (or contraction) of materials.

  2. If thermal expansion is being used, use multiple materials with different coefficients of thermal expansion.

Principle 38. Strong oxidants

  1. Replace common air with oxygen-enriched air.

  2. Replace enriched air with pure oxygen.

  3. Expose air or oxygen to ionizing radiation.
  4. Use ionized oxygen.

  5. Replace ozonized (or ionized) oxygen with ozone.

Principle 39. Inert atmosphere

  1. Replace a normal environment with an inert one.

  2. Add neutral parts, or inert additives to an object.

Principle 40. Composite materials

  1. Change from uniform to composite (multiple) materials.