The systematic Methodology of Inventive Problem Solving known as TRIZ (from the Russian acronym for Theory of Inventive Problem Solving, also known as TIPS) [1,2]), was developed in the former Soviet Union in the 1950's by Genrich Saulovich Altshuller and his colleagues. Today this method is in use throughout the former Soviet Union, where it continues to develop. It is beginning to be taught and commercialized in the United States and Europe. We discuss here the development of TRIZ and provide a short overview of the process involved in conceiving an inventive solution to a problem using the methods provided by TRIZ.

Why is a systematic approach to invention needed?

In a significant sense history is dominated by the progress of invention, from the prehistoric discovery of the wheel to the work of the Thomas Edisons and James Bardeens of our own era. Different inventors have had their own approaches to the art and science of inventing, and this has led to much study of the "creative process". While major discoveries such as the electric light and transistor have profoundly altered our society, innumerable lesser advances have also been necessary to maintain the pace of technological evolution. With the increasing extent and complexity in recent times of our society's knowledge base, though, it has become impossible for inventors, great or small, to keep up fully with advances in many different fields. Thus, relevant inventions in one field may not be known to workers in another, with the result that much effort may be spent in reinventing an existing solution. Fifty years ago, Genrich Altshuller began a quest to overcome this impediment by formulating both a methodical approach to creating an invention, and providing a list of known methods for solving problems that would have relevance in many different fields.

Altshuller examined a large number of patents, looking for the hallmarks of truly creative inventions. He found, to his surprise, that often the same problems had been solved in various technical fields using any of only about forty fundamental inventive principles. As a result, he and his colleagues made a new classification of these patents without regard to their industry basis. By removing the subject matter Altshuller was able to elucidate the problem solving process. He categorized the patents' solutions into five levels:

Level 1. Routine design problems solved by methods well known within the specialty or inside a company. (About 32% of the solutions occurred at this level.)

Example: The ability to change the size of weighted (lead) shoes for divers to fit different size feet by adjusting their length. (It is curious that this development occurred only in the 1960's, some 70 years after the invention of divers' shoes; i.e., for 70 years all divers used uncomfortable shoes of the same size.)

Level 2. Minor corrections (45%) to an existing system, by methods known within the industry.

Examples: (a) Potatoes can rot as a result of bacteria naturally present on their surface. Heating in boiling water kills the bacteria, but too much heat will cook the inside of the potatoes. The potatoes can be exposed for a short time (5 seconds) to a 700°C flame. This kills the surface bacteria without affecting the inside of the potatoes. (b) Welding two different metals together (such as copper and aluminum) can present a challenge. One useful technique is to use a spacer made of a metal which can be welded to both of the incompatible metals.

Level 3. Fundamental improvements (18%) to an existing system which resolve contradictions, by methods known outside the industry.

Examples: (a) Cattle feed consists of various cut grasses which have been mixed with special equipment. Producing the grass mixture by sowing the various grasses together yields a crop which is difficult to till. Further-more, one grass species may suppress the others. The grasses can be sown in narrow parallel strips, and harvested across the strips. Thus, the grasses will get mixed in the receiving bin of the mower. (b) Commonly used methods for moving molten, chemically-active salts require the use of expensive devices. A more economical method uses an air-fuel mixture that is pumped into the bottom of the boiling solution, forming bubbles. As the bubbles rise, they move the salts to the top. Since the bubbles also burn, the molten salts do not solidify. (c) An electromechanical relay element has a finite number of switching cycles. Substituting a cheap semiconductor relay element increases the number of switching cycles and decreases the switching time and weight of device.

Level 4. New generations (4%) using a new scientific (rather than technological) principle to perform the primary functions of the system.

Examples: Microscope, steam engine, photocopy machine, atomic force microscope.

Level 5. Rare scientific discoveries or pioneering inventions (less than 1%) of essentially a new system.

Examples: Discovery of x-rays, penicillin, DNA, laser, high-Tc superconductors.

With each succeeding level, the knowledge required of the inventor, as well as the potential profit from the invention, increases. So do the psychological barriers that can prevent the recognition of a different approach to a problem solution, one that lies outside one's own direct experience. Thus, Altshuller looked for a methodology that by overcoming these psychological barriers, would help in creating higher level solutions. The approach he and his coworkers developed did not to try to reproduce the thinking process of the original inventors, but rather to synthesize a methodology that, if followed, would guide a would-be inventor to the same types of solutions. While common methods of engineering design [3] , by their very nature are based upon the application of established principles to new products, and thus concern themselves for the most part with Levels 1 and 2. TRIZ, by contrast, concerns itself with conceptual approaches, and thus gives its practitioners an opportunity to resolve significant problems up to Level 4. Level 5 discoveries remain out of reach of TRIZ, though work in Russia is attempting to extend the ideas of TRIZ into this realm.

Principles of TRIZ

Altshuller's method is based on three major principles:

(a) The Resolution of Technical and Physical Contradictions

(b) The Evolution of Systems

(c) The Ideal System and Ideal Solution.

The basic concept of TRIZ is the resolution of a contradiction. A contradiction arises from mutually exclusive demands that may be placed on the same system. Improvement of one of the system parameters will then lead to deterioration of others. To resolve the contradiction it is important to find the physical contradictions that are the hidden root of the technical problem. As an example, if the wing area of a plane is large, the plane can take off easily but will be subjected to high drag at supersonic speeds. A compromise solution would fix the wing area at a level that would accommodate both demands, albeit imperfectly. TRIZ rejects such compromises and states the problem starkly: the wings should be large, and they should be small. However, the plane needs large wings and small wings at different times. Thus, the plane can take off easily and fly with low drag using retractable wings.

Altshuller recognized that evolution of any technical system has a characteristic bell-shaped curve when the rate of patent production is plotted as a function of time. Technology follows a life cycle of birth, growth, maturity, and decline (see the theory):

Stage 0. Scientists or technologists make a discovery (corresponding to Solution Levels 4-5) and, often, do not recognize its applications.

Stage 1. A system doesn't exist yet, but important material for its appearance is being developed.

Stage 2. A new system appears as a result of Level 3-4 invention, but development is slow.

Stage 3. Society recognizes the value of the new system and development becomes rapid, with many patents issued.

Stage 4. The system becomes mature, and its development, carried on by the system's specialists, saturates at some level.

Stage 5. Resources for the original system concept are exhausted, opportunity to improve the original system disappears, and the patent production rate drops back toward zero.

Stage 6. The next generation of the system emerges to replace the original system.

Stage 7. Some limited operation of the original system may coexist with the new system.

EVOLUTION OF THE INTERNAL COMBUSTION ENGINE POWERED AUTOMOBILE (The Craig Stephan's example)

Stage 0. Carnot, Watt and others develop scientific understanding of thermodynamics.*

Stage 1. First internal combustion engines (ICEs) are developed.

Stage 2. First constructions of complete automobiles: expensive, "one of a kind", built using inherited techniques of carriage-building.

Stage 3. Ford and other manufacturers initiate mass production of automobiles. The resultant lowered cost brings the automobile within the reach of the average person and spurs a wave of development as manufacturers compete for a large and growing market.

Stage 4-5. Automobiles in the 1950's incorporate at least primitive forms of most non-electronic automotive devices available today (automatic transmissions, power steering/brakes, fuel injection, etc.), but the absence of electronic controls limits their effectiveness in many cases.

Stage 6. Electronic controls coupled to the mechanically-mature ICE powertrain beginning in the 1980's permit sweeping changes in driveability and emissions.

Stage 7. What will ultimately replace the ICE-powered automobile? While electric vehicles, battery or fuel cell powered, exist today, from the standpoint of commercial viability they are still at Stage 1 or 2, awaiting the Level 3-4 inventions that will advance their performance to where they can compete with ICE. If and when these inventions are made, electric vehicles can coexist with the internal combustion vehicle, each dominating the market in which they are the strongest. Thus, Stage 7 can see electric vehicles popular for commuters, with ICE vehicles used for long-distance driving.

* Note that the internal combustion engine is just one of many subsystems that make up the system "automobile".

The characteristics of a given technological system change in a predictable manner as it evolves and matures over time. Genrich Altshuller and Boris Zlotin categorized this evolution into following rules that describe changes in different aspects of a technological system as it matures:

1. Subsystems are originally developed spasmodically, resulting in contradictions. The primitive subsystems with different life cycles hold back the evolution of the total system.
2. The system becomes more dynamic and controllable.
3. The energy/information flows within the system are optimized.
4. The system at first increases in complexity, then becomes simpler as a result of integration.
5. Assemblies are originally made of uncoordinated parts, followed by integrated designs, culminated by parts whose characteristics are changeable upon demand.
6. A transition is made of macro- to micro- objects in the system to further improve performance and control.
7. Human involvement decreases with increasing automation.
8. Any system becomes a subsystem of more general system that is more close to the ideal system

As a system evolves, it should become more nearly perfect, so that its ability to satisfy human needs increases while its cost decreases. The Ideal System, according to the TRIZ ideology, is a non-existent system with all of its functions still being executed. This Ideal System, analogous to the definition of limit in mathematics, is unrealizable in practice. Nevertheless actual systems approach the ideal by increasing their beneficial functions and eliminating harmful factors. One example rapidly approaching this ideal is the modern multimedia computer that performs the functions of TV set, telephone, FAX machine, music center, etc. and has a weight and price thousands of times smaller than the original mainframe computers. Another example is that of an ideal projection screen which is of course ... a wall.

How does TRIZ help with invention?

TRIZ maintains that if the conditions of a problem requiring a creative solution do not contradict the laws of nature, then the problem will have not only the one Ideal Solution but also many other "good" ones. The methodology offers several tools for finding these good solutions. One of them is a detailed algorithm for solving problems, which in simplified form includes the following steps (see the example about the paper for money):

1. Select a technical problem. Usually a system has more than one problem and often the formulation of the main problem is incorrect. TRIZ helps the inventor define the main technical contradiction that s/he wants to eliminate. A technical contradiction represents the conflict between two parts of a system. For example, if undertaking an action A produces a desired effect, but also results in degradation of property B, A and B would lie on two axes of the Contradiction Matrix. Making the choice of technical contradiction marks the transition from a problem situation to the start of the problem solution. About 60-70% of the time, if a technical contradiction is contained in the Contradiction Matrix the inventor is able to go immediately to step (4) and use the corresponding inventive principle.
2. Formulate a physical contradiction. The inventor should replace the technical contradiction with a physical one in the following form: A given element should have the property A to execute a necessary function, and should have the property "anti-A" to satisfy other conditions of the problem. A physical contradiction results from incompatible requirements on the physical condition of the same element. Successful formulation of a physical contra-diction usually shows the problem's nucleus. Intensifying the contradiction often makes the problem solution straightforward, so the inventor can use lists of effects at step (4).
3. Formulate an ideal solution. At this step the inventor should decide how to increase the beneficial factors and eliminate harmful factors. Comparison of the result with the ideal solution demonstrates whether the inventor was right or not in the choice of the major technical contradiction. The ideal solution works as a goal in steps (4-6).
4. Find resources for the solution, making use of the capabilities of TRIZ. At this step the inventor should use the knowledge base and instruments of TRIZ (see below )
5. Determine the "strength" of the solutions and choose the best one. Here TRIZ recommends comparison of one's solutions with the Ideal Solution and evaluation of the results with a cost-benefit-type analysis. At this point the solution of the problem is accomplished. Usually, the solution is at Level 2-3 if a Technical Contradiction has been resolved, and at 3-4 is a Physical Contradiction has been resolved. The next two steps are used to predict the development of the system in the future and to improve the TRIZ process itself.
6. Predict the development of the system considered within the problem. At this step the inventor should use the TRIZ laws of evolution of technical systems and forecasting techniques. This step allows one to see potential future problems in the system, its subsystems and the super-system (the larger system in which the system considered is itself a subsystem), and to choose possible methods for their solution. In general, this step leads to future work to improve the system and increase the competitive position of the inventor. TRIZ offers a new thinking method, in which one's problem is considered as a "system of systems".
7. Analyze the solution process in order to prevent similar problems. This step allows the inventor to improve the algorithm itself. There are several versions of the algorithm from its first exposition comprising 5 steps to its current form with about 100 steps.

TRIZ continues to undergo development, with several academic groups in the former Soviet Union. A special TRIZ magazine is published in Russia. Examples of the work include continued development of the algorithm, additions to the lists of physical, chemical and biological effects, searches for new methods to overcome psychological barriers, adaptation of TRIZ for various students ranging from elementary schools to colleges (in the latter different TRIZ courses from 40 to 240 hours long are available), and publication of some 50 books about TRIZ. The popularity of TRIZ is growing fast in U.S., Europe, Japan and other countries. Whereas TRIZ is taught in dozens of schools in the former Soviet Union, it is just beginning to develop as an academic course in the U.S. and Europe. The theoretical basis of TRIZ is being extended to provide effective solutions to creative problems in non-technical areas as well, such as functional-cost analysis, marketing strategy, and advertising.

References:

[1]. G. S. Altshuller. Creativity as an Exact Science: The Theory of the Solution of Inventive Problems. (Translated from the Russian by Anthony Williams.) New York: Gordon and Breach, 1984. A theoretical development of the method, with many examples, though somewhat dated.

[2]. H. Altov. And Suddenly the Inventor Appeared. (Translated and adapted from the Russian by Lev Shulyak.) Worcester, MA: Technical Innovation Center, 1994. This book, written by Altshuller under a pseudonym, is aimed at secondary school students and while not rigorous in its development, provides an entertaining look at how the methods of TRIZ can be applied to a variety of problems.

[3]. G. Pahl, and W. Beitz, Engineering Design. Berlin: Springer - Verlag, 3-rd edition, 1995. A systematic approach, developed in Germany, to the whole design process from task clarification to detailed design.

[4]. Semyon D. Savransky, Engineering of Creativity CRC Press, 2000. 

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