The Seventy-six Standard Solutions, with Examples - Class 5

John Terninko,
Ellen Domb,
Joe Miller,

The “76 Standard Solutions” of TRIZ were compiled by G.S. Altshuller and his associates between 1975 and1985. They are grouped into 5 large categories or classes as follows:


1.     Improving the system with no or little change                       13 standard solutions

2.     Improving the  system by changing the system                      23 standard solutions 

3.     System transitions                                                                 6 standard solutions

4.     Detection and measurement                                                17 standard solutions

5.     Strategies for simplification and improvement                       17 standard solutions

                                                                                    Total:  76 standard solutions

(References 1-5, 12)


This series of articles began in the February, 2000, issue of the TRIZ Journal, with a tutorial article and the Class 1 problems and solutions.  Class 2 appeared in the March, 2000, TRIZ Journal, Class 3 in May, and Class 4 in June.   In the spirit of Altshuller, we want to make these interpretations  available to all who are studying and using TRIZ.


Typically, the 76 standard solutions are used as a step in ARIZ, after the Su-field model has been developed and any constraints on the solution have been identified.   The model and the constraints are used to identify the class and the specific solution.   As in other TRIZ instructional material, examples are used to show the application of the standard solution to a wide variety of problems from many fields.


The solutions in classes 1-4 frequently make the system more complicated, since many of them require the introduction of new materials or new fields.  The solutions in Class 5 are methods for simplifying the system, making it more ideal.    After deciding on a solution from classes 1-3 for a performance problem or class 4 for a measurement or detection problem, use class 5 to simplify the  solution.  See Figure 1 for a flowchart showing in more detail the use of  the  various classes of the 76 standard solutions for both problem solving and technology forecasting.

Figure 1.  Flowchart for the use of the 76 Standard Solutions.  (References 12 and 1)


Class 5.  Methods for Simplifying and Improving the Standard Solutions. 


5.1. Introducing Substances


5.1.1. Indirect ways Use “nothing” –add air, vacuum, .bubbles, foam, voids, hollows, clearances, capillaries,  pores,  holes,  voids, etc.


Imagine creating warm clothing for swimming underwater.  The standard thinking is to increase the thickness of rubber.  The suit will become very heavy, so making it thicker is not acceptable.  Adding nothing to the rubber creates a foam which weighs less with more thermal insulation. This is the current wet suit.

Similarly, a fireproof replacement is needed for wood shingle roofs.  Concrete is fireproof, and can be made to look like the shingles, but it is too heavy for the structure of a house originally designed for a wood shingle roof.   Air is passed through the concrete while it is setting, to make a concrete foam that is fireproof and light weight. Use a field instead of a substance. 


It is necessary to check the hermetic seal during production of small plastic mustard packs for single servings used at fast food stores.  A complex system is described in 4.. using water pressure and an optical system.   A much simpler system can be made using vacuum:   a sample of packs are put in a vacuum chamber, and then the air is removed.  .  Good packs puff up and bad packs leak mustard.   We have used the field of the pressure differential between the pack and the atmosphere to detect bad packages.

To find a stud behind a wall, without drilling holes in the wall, three kinds of field detectors are in common use:  1.  Tap on the wall and listen to the differences between open areas and the stud.  2.  Use a magnet to detect nails, since they will be in the stud.   3.  Use an ultrasonic pulse generator and detector, since the stud will return a much stronger echo than the open space. Use an external additive instead of an internal one.  


The sheet metal in the earlier example is the external additive.  (See 1.2.1)  This is a much simpler solution than making complex changes to the jack. Use a small amount of  a very active additive. 


Use thermite explosive to weld aluminum to something else.  Conventional welding for aluminum requires very high heat and corrosive chemical etchants..

Parts per million of dopants in silicon can change its electronic properties enough to govern the properties of an integrated circuit.  Doping the Si with the additive to get the right properties makes it possible to operate the circuit at much lower voltage, with much smaller circuit elements than older designs. Concentrate the additive at a specific location.


Spot location of spot removal chemicals.  Sticks of detergents and sprays of enzymes are commercially available products for this purpose.  This removes the spot, without subjecting the whole garment to the extra wear of the strong chemicals

Therapeutic agents located at the exact location of the disease,  tagged to realease in a preferred organ.  The use of iodine to carry other medication to the thyroid is an example.  This avoids dosing healthy parts of the body with medications that have severe side effects.

Concentrate fluoride at the site of beginning tooth decay, to remineralize the tooth and avoid destroying a large amount of the tooth with a conventional filling. Introduce the additive temporarily.


Chemotherapy for cancer patients.   Very toxic chemicals are introduced for a short period of time.  They damage the cancer more than they damage the healthy tissue during the short time, then they are flushed out of the patient’s system.

For certain kinds of bone injuries, a metal screw is placed in the bone while healing starts, then removed.  Ref. 4. Use a copy or model of the object  in which additives can be used, instead of the original object, if additives are not permitted in the original.  In modern use, this would include the use of simulations, and copies of the additives.


Video conference calls or computer video conferences permit meetings where all the participants are not in the same place.  

The video tape of Genrich Altshuller shown at the TRIZCON99 (after his death) was an additive to the meeting that was otherwise not available.

Test changes to complex electrical or mechanical devices (test the additives) on a simulation, rather than by building new devices for each test. Introduce a chemical compound which reacts, yielding the desired elements or compounds, where introducing the desired material would be harmful.


People need sodium for metabolism, but metallic sodium  is harmful. Ordinary salt is ingested, then converted to sodium and chlorine for use by the body.

Race cars use nitrous oxide instead of air for combustion to get higher power Obtain the  required additive by decomposition of either the environment or the object itself. 


Bury garbage in the garden instead of using chemical fertilizers, to get the benefit of adding fertilizer without the side effects and wasted energy of the chemicals.


5.1.2. Divide the elements into smaller units. 


Faster airplanes  require larger propellers but as the length increases the tip   will be going faster than the speed of sound, causing a shock wave.  Two smaller propellers are better than one large one.

Similarly  for compressors in jet engines, air conditioners in a factory,  etc.


5.1.3. The additive eliminates itself after use.  Examples:

A complex shape can be "sand" blasted with dry ice and have no residue to clean when the dry ice sublimes. Use of sand, artificial sapphire particles, etc., leaves residue and requires clean-up.

Fuseable webbing is a nonwoven fabric  that is  stitched into a garment to  reinforce high stress areas.  After the garment is completed, it is ironed and the  webbing disappears, becoming part of the fabric.  The older style interfacing remains a separate fabric layer throughout the life of the garment and can separate, shrink, and wrinkle, causing the garment to fit badly.

Dissolvable sutures are absorbed by the body when the injury heals.  Older style sutures require a separate medical procedure to remove the sutures, causing pain, inconvenience, and the possibility of infection.


5.1.4. Use “nothing” if circumstances do not permit the use of large quantities of material.   Example:

Use an inflatable structure where the weight of a solid object would not be safe.  Inflatable “jacks” are used to lift aircraft out of swampy terrain where mechanical jacks would sink due to their own weight.

Use an inflatable mattress for guests, then deflate it for compact storage.  This is comfortable for the guests, less expensive than sending them to a hotel, and more convenient for the hosts than having to maintain a guest room during the time when there are no guests.


5.2. Use fields


5.2.1. Use one field to cause the creation of another field


A Therma-RestTM pad is a backpacking self inflating mattress. The mattress is stored or carried compressed, with the air expelled and its air vent closed.  Inflation is caused by the memory of the compressed foam.  When the air valve is opened expansive mechanical force generated by the compressed foam creates structure and causes a pressure difference to draw air into the cells.  The vent is then closed and the mattress remains inflated even under the sleeper’s weight.

Dipolar plastic films are welded by the internal conversion of radio-frequency  energy into heat.  This produces heat at the optimum location for welding multiple pieces of plastic together, and does not require heat to be conducted through the materials.

In a cyclotron, magnetic fields accelerate particles.  The acceleration produces Cherenkov radiation (light).  The wavelength of the light can be controlled by varying the magnetic field.


5.2.2. Use fields that are present in the environment.  Examples:


Electronic devices use heat generated by the individual components to cause air flow through the device for cooling, without the addition of cooling fans.  This may allow improved performance of the overall design.

Autopilot steering and controls for sailboats and airplanes use small vanes (called “trim tabs”)  on the control surfaces that use the pressure of the water or the wind to move the control surfaces to the desired angle.


A battery powered radio intended for emergency use can also have photovoltaic cells for recharging the battery by sunlight.  This allows battery weight and size to be minimized.  A further improvement that can further minimize the need for a battery is to use a hand wound spring driven generator.  This utilizes the field of mechanical energy always available from a person in the environment, even in the dark.


5.2.3.  Use substances that are the sources of fields. Examples:


In the example of 5.2.1 for welding dipolar plastics, the plastic material surrounding the weld can be used as a heat sink (thermal field) for cooling the actual weld junction.

Pellets of radioactive material are implanted in a tumor, in order to get gamma rays to damage the tumor directly.  This is also an example of, since the pellets are removed after a short time.

In an automobile, the hot engine coolant is used as a source of thermal energy (a field) to provide heat for the passengers, rather than using fuel directly.


5.3 Phase Transitions


5.3.1. Phase Transition 1: Substituting the Phases.  Examples:


Use a-brass instead of b-brass.  (The crystal structure changes, which changes the mechanical properties, at a particular temperature.)

Use gas, liquid, or solid phases of the same material, depending on the temperature/pressure/volume conditions.  Natural gas is transported as a cryogenic liquid to save space, then expanded and warmed for use as a gaseous fuel.


5.3.2. Phase Transition 2: Dual Phase State.  Examples:


In ice skating,  friction is reduced by  using  the phase change of ice to water under the blade, which then changes back to ice and renews the surface of the area.

Plastic containers for drinks are stressed in two directions.  First the plastic  is injection  molded and cooled, then heated to just below the glass transition temperature and blow molded, which orientates the plastic, making it clear and stronger than conventional blow molding.


5.3.3. Phase Transition 3: Utilizing the Accompanying Phenomena of the Phase Change.  Examples:

Hand warmers for sports or for outdoor work  consist of  a plastic pouch containing a liquid which goes through an exothermic conversion to a solid,  triggered by the acoustic energy from bending a thin metal disk in the liquid.  The system is “recharged” (restored for the next use)  by placing it in hot water or a microwave oven to raise the liquid above the transition temperature.

See 2.4.7.  Another example for superconductors is that when metallic superconductors reach zero electrical resistance, they become very good thermal insulators, and can be used as thermal switches to isolate low temperature devices.


5.3.4. Phase Transition 4: Transition to the Two-Phase State.  Examples:


Make  a variable capacitance, using a  "dielectric-metal" phase transition material.  When heated some of the layer becomes a conductor and when cooled it becomes a dielectric.  Capacitance is controlled by temperature.

Gaseous Si is more easily doped than the solid.  The doped gas then can grow epitaxially on the solid substrate and make a better crystal structure with more uniform doping than a treated solid.


5.3.5. Interaction of the Phases.  Increase the effectiveness of the system  by inducing an interaction between the elements of the system, or the phases of the system.


Make brandy with double distillation and age it  in wooden casks.  The is an interaction between the wood and the liquid.

Hydrogen gas can be stored in much higher densities than in its gaseous form by binding it in platinum and palladium sponges.

Use chemically reactive  material as the working element of a heat cycle engine.  The dissociation of the material under heating and the recombination when cooling improves the function of the engine (The dissociated material has lower molecular weight and therefore transfers heat faster.)


5.4. Applying the Natural Phenomena (Also called “Using Physical Effects”)


5.4.1. Self-controlled Transitions.  If an object must be in several different states, it should transition from one state to the other by itself. 


Altshuller’s famous lightning rod that protects a radio telescope (used to illustrate the steps of ARIZ,  ref. 10) is a tube filled with low pressure gas.  When the electrostatic potential in the area is high, as before a lightning discharge, the gas in the tube ionizes, making a preferred path for the lightning.  When the lightning has discharged, the gas recombines, and the environment of the device being protected is neutral.

Photogray™ glasses become dark in  light the environments and more transparent in dark environments.


5.4.2. Strengthening the output field when there is a weak input field.  Generally this is done by working near a phase transition point.


For scuba diving, you need to store large amount of high pressure gas, typically 80 cu.ft. at one atmosphere, stored at  3,000 psi.  The small pressure difference between the external ocean pressure and the inhalation pressure of the diver’s breath is used to control a valve that regulates the flow of gas.

The vacuum tube, relay and transistor can all be used to control very large currents with very small currents.

Formation of bubbles in superheated liquid indicate very small ionization centers.  The bubble chamber for detection of elementary particles works on this principle.


5.5. Generating Higher or Lower Forms of Substances


5.5.1. Obtaining the Substance Particles (Ions, Atoms, Molecules, etc. )  by Decomposition.   


If hydrogen is needed and not available in the system, but water is available, convert the water to hydrogen and oxygen by electrolysis.  If atomic oxygen is needed, use ultraviolet light to dissociate ozone.

G. Altshuller’s first patent as a teenager, for generating oxygen from hydrogen peroxide to aid in underwater diving, provides an excellent example of obtaining a substance particle in the desired form by decomposition.

The catalytic converter in a car converts “bad” molecules into “good” molecules.   It converts NOx  and air to nitrogen and water.


5.5.2. Obtaining the substance particles by joining. 


The Bacteria  Thiobacillus ferrooxanads  is used to convert metallic iron into iron oxide in the slag piles of gold mines.  The iron oxide is soluble in water so it is easily removed, leaving a higher concentration of gold to be processed conventionally! (Ref. 11.)

A tree takes in water and carbon dioxide and, using sunlight and photosynthesis,  produces wood, leaves and fruit.



5.5.3. Applying the Standard Solutions 5.5.1 and 5.5.2.  If a substance of a high structural level has to be decomposed, and it cannot be decomposed, start with the substance of the next highest level.  Likewise, if a substance must be formed from materials of a low structural level, and it cannot be, then start with the next higher level of structure.    In the antenna problem (5.4.1)  the gas molecules are ionized, not the whole antenna, to create the path for the lightning, and the ions and electrons are recombined to restore neutrality.



1.  “Golden Classics of TRIZ,” 1996, Ideation International, Inc. and Tools of Classical TRIZ, Ideation International, Inc., Southfield, MI, USA, 1999.

2.  “Invention Machine Laboratory,” version 1.4,  1993.  Invention Machine Corporation.

3.  G. Gasanov, B. M. Gochman, A. P. Yefimochkin,   S. M. Kokin, A. G. Sopelnyak, Birth of an Invention:  A Strategy and Tactic For Solving Inventive Problems.  Moscow: Interpraks, 1995. (In Russian)  Chapter 6 and Appendix 9. 

4.  J. Terninko, A. Zussman, B. Zlotin, Step-by-Step TRIZ.   Responsible Management, Nottingham, NH, USA. 1997.

5.  H. Altov (Altshuller pseudonym). And Suddenly the Inventor Appeared. Translated by Lev Shulyak.  Technical Information Center, Worcester, MA, USA.  1994.

6.  J. Terninko, E. Domb, J. Miller, E. MacGran, The TRIZ Journal, May, 1999.

7.     Ideation International.  IWB Software, 1999.

8., US patent 4,357,021, US patent 5,461,677

9.     US patent 4,286,080

10.  G. Altshuller.  Creativity as an Exact Science.  Translated by Anthony Williams.  Gordon and Breach, NY, 1988.

11. D L Stoner et al., "Use of an Intelligent Control System to Evaluate Multi-Parametric Effects on Iron Oxidation by Thermophilic Bacteria", Applied & Environmental Microbiology, Vol 64 , No 11, Nov, 1998.  See also Jacob Skir, “Gold recovery and the biological effect. “  The TRIZ Journal, June, 1999.

12.  Y. Salamatov.  TRIZ:  The Right Solution at the Right Time. Edited by Drs.V. Souchkov and M. Slocum, translated by M. Strogaya and S. Yakovlev.  Insytec, The Netherlands,  1998.

References 1,4,and 12  are available from the Products and Services page of the TRIZ Journal. 


Note of Gratitude:
Our thanks go to Zinovy Royzen for sharing his method of Su-field modeling called TOP modeling.  See  “Tool, Object, Product (TOP) Function Analysis” in the September, 1999, issue of The TRIZ Journal,