Two Pluses 6

Trends of Evolution

by Kalevi Rantanen
Brahenk. 9 E 18
phone/fax +358 2 251 1623

Last updated August 19, 1997

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The concept of evolution trend

Regularities in development . Trends of evolution are regularities observed
in the history of technology. Most regularities are statistical trends, but there are some trends
which we can consider as universal laws. Laws and regularities are formulated as the result
of the the study of huge mass of innovations and inventions.

"Short cut". By the trends we can try to forecast "directly" a solution and features
of an ideal system.

SystemFeature 1Feature 2
Ideal final

How to get benefits from the trends?

Trends are useful tools in many ways:
  1. We can choose right problems. Does the solution, if achieved, simplify the system
    compared to functions and features? Will the useful features from alternative systems
    used? Are the old techonologies used to get a new solution? Does the solution, if
    achieved, fulfil the requirements of the ideal final result?
  2. We can decrease risks. Projects, not directed to the ideal final
    result, can be rejected, and losses avoided.
  3. We can detect weak signals. Trends help to see new opportunities, as well as
    new conflicts and problems, in the same beginning
  4. We can begin to develope next-generation products before competitors. Due to
    detecting weak signals we can begin good projects more early.
  5. We can improve investment decisions. Trends help to select promising projects and
    invest money more effectively.
  6. We can find invisible customer needs. Often customers cannot pronounce their needs in the
    future. Trends help to identify new needs.
  7. By forecasting needs trends enable to create customer-focused quality.
  8. We can find new problems. Trends show which problems can appear.
  9. We can collect and create knowledge effectively. Trends help to select and classify
  10. We can make more reliable techological forecasts by the trends

Universal laws

Regularities appearing always. Some universal rules are hidden in the Two
Pluses Matrix. If we have a problem or "minus", the system should have useful features,
"pluses", too. If it hadnīt, we could simply remove the whole system. When the system
evolves, minuses disappear and pluses remain. The ideality of the system grows
inevitably. The ideal final result has again some new minuses, and the cycle is
repeated. The features of alternative systems are combined. The result is a
bisystem. A new bisystem is again combined with an alternative system. The
result of successive feature combinations is a polysystem. So we can formulate
three general laws:
- the spiral of evolution
- the increasing ideality of a system
- trend mono-bi-poly
In all innovations we can see the influence of these three laws.

A spiral of evolution
The line of evolution: Contradiction - ideal final result - contradiction - ideal final result - etc.
Minus - plus - minus - plus - etc. Increasing complexity - trimming - increasing
complexity - trimming etc.

For example the history of the bicycle:
A solution: a horselike frame with two wheels in 1791
A new contradiction: you can move sitting on the wood horse, but how to steer the vehicle?
A solution: a front wheel which can be turned (Karl v. Drais 1817)
A new contradiction: you can steer, but cannot get speed enough kicking by legs
A solution: pedals in 1861 (Pierre Michaux), "boneshaker"
A new contradiction: higher speed requires bigger wheel ("Ordinary" bicycle appears), but
a big wheel is uncomfortable
A solution: a chain-drive rear wheel in 1885 (John Kemp Starley)
A new contradiction: more speed means more vibration and shocks
A solution: pneumatic tires in 1888 (Dunlop)
A new contradiction: cranks are rotating all the time, whether it is needed or not
A solution: freewheel 1894
A new contradiction: a bike was impractical for off-road riding
A solution: the mountain bike in 1970s Etc.

The ideality of the engineering system
Different types of ideal systems: Ideal machine. Ideal process. Ideal material. A system
simplified by trimming

For example the history of the bicycle:

Improving features compared to weight. An all-metal bicycle in 1870s weighed
about 25 kg. A bicycle in 1990, built using composites, weighed 12 kg. At the same
time features are increased and improved.

Trend mono-bi-poly
Successive combining of alternative systems.
Combining of devices, processes, problems, ideas, solutions, etc

For example the history of the bicycle:
In the same beginning the bicycle combined two ways of transport: riding a horse and
walking. The first bike was a hobby-horse with two wheels. A cyclist sat on a beam and
and pushed the feet against the ground. Karl von Drais removed the head of hobby-horse
and converted the front wheel into a steering mechanism. So the cyclist could turn the
vehicle like the rider guiding the horse. When the pedals where invented, the bike could be
driven without the feet touching the ground. When the chain transmission was introduced,
the cyclist could already sit on the saddle as comfortably as on horseback. The development
of the mountain bike in 1970s added yet one feature of the horse: capability to run outside

The basic concept of the bicycle is the bisystem combining the pluses or good FEATURES
of riding and walking. Today we donīt usually think of the mount as one prototype of the
cycle. But in 19th century people often compared the bike to the horse. The bicycle was
"the horse who is saddled all the time and eats nothing".

If the initial bicycle concept can be considered as a bisystem, the mature bike is a polysystem
combining many features and technologies:
- Wire-spoked tension wheel, patented by Edward Cowper in 1868, but invented by George
Cailey fon an aircraft already in 1808
- Chain transmission
- Pneumatic tire, patented by John Dunlop 1888, but used by R. W. Thompson already 1846
in a horse-drawn brougham
- Lamps, cyclometers, bells etc.
- In last years electronics, as different meters and microchips for detecting stolen bikes

For example the history of electronics:
- Monosystem: doped semiconductor (p or n)
- Bisystem: two semiconductors - diod (pn-junction)
- Bisystem: two diods - transistor (pnp or npn)
- Polysystem: great number of transistors, for example 5 millions
- Polysystem: electronics embedded in all sorts of devices and machines, mechatronics

Many systems outside technology are polysystems:
- Ways of marketing
- The quality cultrure of a company
- The core competence of a company
- The cluster of many companies

In activity systems or in polysystems of organisations one can often see very clearly, that isolated
parts are weak or totally worthless, but the composition generates the superior quality.

Statistical trends

About the system of trends
We call statistical trends the lines of development which are seen when a great number of
innovations are studied. For example, one has detected that a solid monolith often
evolves to a porous subject. The trend doesnīt mean that always when we have a
solid object, the following stage of development should be a hollow body. But the
statistical trends give interesting hypotheses.

In different sources a little bit different systems of trends are presented. The presentation
here is based mainly on IMLab software and works of Altshuller, Salamatov, Linde and

Trimming trend
The line of evolution:
The engineering system evolves to the more trimmed structure. The same function
is carried out by smaller number of parts or processes.

Examples, the history of the bicycle:
Wheel with many spokes - with three or
four spokes - with one "spoke" or a disk wheel. Frame from may tubes - one tube
frame (monocoque).

Lines of evolution (according to IMLab SW):
Introduction of void: Monolith - a void - many voids - porous system - dynamized voids.
Monolith - plates/brush - loose body - paste - liquid/foam - gas -
vacuum - field.

Examples from the history of the bicycle:
From mechanic to hydraulic brake
The evolution of a tire: a solid rubber tire - a spongy rubber one - a pneumatic one

For example cleaning of surfaces:
Monolith (brush, balls) - liquid (water) - solid/gas (carbon dioxide) -
field (sound/ultrasound, microwaves)

Evolution of electronics: from single and big transistor to schemes containing millions
of small ones

From substance to field:
Common train - air cushion train - magnetic levitation (maglev) train
Mechanical lifting device - "pneumatic" (suction) - magnetic
Transistor: from a junction transistor to field effect transistor

The line of evolution (IMLab):
immobile system - a joint - many joints - elastic system - liquid/gas - fields
Generally: the system capable to change its properties

Examples from the history of a bicycle: tire, suspension, a spoke wheel which also
works as a suspension and a shock absorber.
Other examples: an air cushion in the car, traffic signs which can change according to
weather and traffic density

Lines of evolution:
Geometrical form and materials
Rhythm (IMLab): No vibrations - vibrations - resonance - vibrations coordination -
- standing/traveling waves
Coordination in time and place:
An electrically assisted bicycle is interesting because of additional power is provided
during acceleration and climbing.

Hand and scissors (Fiskarsī Classic)
Reducing noise: "Antinoise"

Objects Interaction
Lines of evolution (IMLab):
Interaction - introducing foreign substance - introducing resource substance -
- coordination in time/in space - trimmed interaction
Introducing Additives
Into object - between objects - onto objects - into surroundings

An example of introducing additive:
More healthy salts: by adding potassium chlorid and magnesium sulfate to common salt
(NaCl) harmful side effects are decreased and the taste preserved

An example of using resource substance:
To increase washing efficiency washing material is usually added to water. Steam washing
allows to exclude washing chemical, or water itself is used as "additive"

Improving energy conductivity
The line of evolution:
More developed systems "conduct" energy better.

The history of a bicycle: a reduced weight, a chain transmission and other improvements
have allowed to converse the muscular energy better to kinetic energy.

Another example: A typical chain of energy conversion is first to get hot gas, second to get steam,
third to get mechanical energy, and fourth to get electrical energy. New energy technologies
make the chain shorter. For example conversion of heat directly to electroenergy.
Anders Killander proposes to use one of thermo-electric effects, Seebeck effect,
for getting small amounts of electric energy from a wood-fired stove.
See A. Killander. Generating Electricity for Families in Northern Sweden,
TRIZ Journal, January 1997

The change of the quantitative features of the system in time follows a well-known
S-curve. It is not possible to forecast the shape of the curve. But it is
useful to think about where on the curve we may be and how the curve can evolve in

Curves in the history of a bicycle:
- "Draisienne"
- Cranks and pedals added
- Ordinary with large wheel
- Safety with the rear-wheel chain drive
- Last big wave: mountain bike
- The increasing diameter of a wheel in 19th century, before the chain transmission
- Materials: steel, aluminium, composites

Study of trends with a computer

Module IM-Prediction in IM Lab presents several trends grafically, see IMLab.

- IMC has just released new software package TechOptimizer 2.5 Professional Edition,
in which are considered 20 engineering system trends, see
Invention Machine Corporation

Examples of applications

The evolution of the bicycle.

Letīs try to envision the future of the bicycle. Spirals of evolution:
The diameter of a wheel. The invention of a chain transmission in last century shrinked the
wheel to the common diameter today. We can forecast the following cycle: maybe the electrical
transmission allows to make a wheel much smaller. A new question: efficiency of electrical
transmission? The weight of devices?
The faired bicycle is weatherproof. A new problem: the windsail effect. A new solution: a low
centre of gravity.

Increasing idealness. We can predict the improvement of aerodynamics. A recumbent with a
fairing can cut drug by about 70 per cent compared to a a standard bike. Compare with a car.
Aerodynamically a common bicycle reminds of the car in the beginning of century.

Possible bisystems or feature combinations:
- The features of a diamond frame AND a monocoque frame
- The features of a common or upright bike AND a recumbent
- The features of chain drive AND belt drive

Mono-bi-poly. Feature transfer from motorcycles to bicycles. The combination of the features of
small cars and bicycles. Improvements in environment, related to the development of bicycle.
For example roads with roofs - tubes for bicycle drivers.

The polysystem of solutions. The bicycle of future may be collected from the technologies known
today, or more exactly, from the features of old technologies. For example:
- Monocoque frame (Lotus)
- Small wheels (Alex Moulton)
- Electic motor for acceleration and climbing (for example Yamaha)
- Automatic belt transmission (for example Spinenergy)
- Etc.

Trimming. Simplifying of chain to one part. From many spokes to one "spoke".
Simplifying the transmission.

Segmentation. Chain. Bearings. We can wait "microlevel solutions".

Dynamization. Collapsible bikes will be improved and become more common. Use of
computers. An electronic control already makes possible to set the bike to automatically
set gear ratios to maintain a certain speed, pedalling cadence, or heart rate. Try to
imagine evolution in future!

Coordination. Bicycle, better compatible with the cyclist. Shape, structure, optimal physiological

Increasing idealness. Less weight related to strength, safety and other features.
Lubrication: the ideal lubrication is the lubrication which is not needed.

The fixing problem. Letīs consider the "fixing problem" by trends.
Mono-bi-poly: Feature transfer from different "fixers" to a simple original system.
Segmentation: Brush constructions. Gas: suction. Electrical field.

About the evolution of paper. Evolution of interactions. Electric and magnetic


Exercise 1. Study the evolution spiral of your system.

Exercise 2. Apply the trend of increasing idealness to your own system.

Exercise 3. Apply the trend mono-bi-poly to your own system. Can you
find an analogous line of development?

Exercise 4. If you have software IMLab or TechOptimizer Pro,
use software when you apply the segmentation trend to your own system (trend mono-bi-poly,
Prediction Tree: Multiplied interactions)

Exercise 5. Apply the trimming trend to your own system. Can you
find an analogous line of development?

Exercise 6. If you have software IMLab or TechOptimizer Pro,
use software when you apply the trimming trend to your own system (Prediction Tree: Trimming,
in TechOptimizerissa also Trimming trend)

Exercise 7. Apply the segmentation lines to your own system. Can you
find analogous lines of development?

Exercise 8. If you have software IMLab or TechOptimizer Pro,
use software when you apply the segmentation trend to your own system (Segmentation trend,
Prediction Tree: Boosting, Segmenting)

Exercise 9. Apply the dynamization trend to your own system. Can you
find an analogous line of development?

Exercise 10. If you have software IMLab or TechOptimizer Pro,
use software when you apply the segmentation trend to your own system (Dynamization trend,
Prediction Tree: Boosting, Dynamization)

Exercise 11. Apply the coordination trend to your own system. Can you
find an analogous line of development?

Exercise 12. If you have software IMLab or TechOptimizer Pro,
use software when you apply the segmentation trend to your own system (Rhythm Coordination
trend, Prediction Tree: Boosting, Coordination)

Exercise 13. Transform the Ideal Final Result using trends of development.

Exercise 14. Consider costs and market opportunities:
- How to improve cost-effectiveness by the study of trends? Cost limits?
- Which quality benefits and market opportunies the trends can show?

Improving Ideas by Two Pluses Matrix

SystemCombatibilityNumber of

Further reading

This TRIZ Page.

  • From two pluses to many pluses: see Many Pluses.

    Articles in TRIZ Journal

    Books and videos

    Updated August 19, 1997

    Use of Knowledge
    Next tutorial: Structural Standards
    Return to TRIZ Page (home page)