Aggiornamento: 8 nov 2021
TRIZ engineers are comfortable with paradox, contradiction and ambiguity – as was Leonardo da Vinci and many great inventors. Every engineering problem contains at least one contradiction but for many engineers contradictions remain unnecessarily associated with uncertainty, difﬁcult choices and compromise: unnecessary because there are a small and ﬁnite number of practical answers to solving any contradiction, which are all simple basic principles, and help every engineer solve any problem. Unnecessary also because this invaluable and powerful list of answers, the TRIZ 40 Inventive Principles, is public domain and has been openly used in Russia for over 50 years and more recently has been freely accessible to almost everyone. Contradictions are solved by applying the relevant TRIZ Inventive Principles which are simple ways of achieving clever solutions. They are straightforward and easy to understand. Some examples are shown below.
What is a Contradiction?
A contradiction is a simple clash of solutions. Either we want opposite solutions, or by introducing a new solution, i.e. an improving change to one feature in a system, another feature in our system has got worse. Engineers recognize contradictions as familiar situations, such as when we improve strength by adding more material we ﬁ nd that this solution often makes weight get worse. Contradictions can also be the need for opposite beneﬁ ts which are achieved with opposite features or functions an everyday item such as an umbrella has the beneﬁ ts of being both large and small. There are many situations of wanting opposites such as white and black, TRIZ shows us all the way to achieve such opposite beneﬁts. Achieving opposite beneﬁts/opposite features within a system may initially seem impracticable and silly – even though every polar bear has solved how to be both black and white (it has black skin for warmth but its transparent fur allows it to appear white to merge into the snowy landscape). The clever polar bear solution and all other clever answers to contradictions are in the TRIZ 40 Inventive Principles to help engineers systematically ﬁnd simple and useful solution triggers to questions that at ﬁrst glance may seem impossible.
Altshuller studied thousands of patents to extract solutions and concepts from the clever ones. He deﬁned a clever patent as one that offered solutions to contradictions and/or cleverly applied knowledge from another industry. He found that about 20% of patents were ‘ clever ’ and he noted all the successful concepts they employed. After 35,000 patents he had allegedly found just 37 concepts for solving contradictions and after 50,000 patents had found only 40 concepts – known as the TRIZ 40 Inventive Principles.
Today after millions of patents have been analysed we still stand at these 40 concepts/principles for solving a contradiction. These 40 Inventive Principles are simple solution triggers ( ‘ tricks ’ Altshuller called them in his book he wrote for children And Suddenly the Inventor Appeared ) to show us all the ways the world knows to solve particular contradictions. So once we uncover contradictions TRIZ directs us to the relevant 40 Principles which will help us solve our contradictions. These powerful solution triggers then need to be turned into practical ideas; this process needs relevant knowledge combined with brain power and experience to produce practical and relevant solutions to contradictions.
I get something good but I then also get something bad.
We think of a solution to improve something but something else gets worse.
Often we assume that when faced with this dilemma that we must choose one solution, technical parameter or feature at the expense of the other – without TRIZ we initially assume we can ’ t have both. We believe that the two features are inevitably linked and that when we improve one, then the other will inevitably get worse in some way.
Simple examples of Technical Contradictions occur everywhere:
■ Digital camera – we want small pixels (better resolution) but this gives us increased noise.
■ Cooling fan – how can we get good airﬂ ow, but without noise?
■ A larger heat sink dissipates more heat but is bigger.
■ I enjoy eating cream cakes but they are bad for me.
We want opposite solutions – for example, high and low.
We want a high garden fence for our garden boundary – but we also want a low fence so it doesn ’ t get blown down in high winds. Clever solutions to such contradictions exist in the world – we have to ﬁnd a fence that is there for privacy but not there for high winds – and such fences exists and is called a Hit and Miss.
Physical contradictions are solved by separating the solutions in different ways which gives both solutions. We can separate in time, in space, on condition or in scale.
- Separate in time means having one solution at one time (long board pointer) and the opposite solution at another time (short board pointer).
- Separate in space means to have one solution in one place (cold outside of coffee cup) and the opposite in another place (hot inside cup).
We use the separation principles – separate in time and space etc. – to see how to get systems to give us opposite requirements but at different times and in different places. Separate in time examples are everywhere as there are many situations and occasions when we want systems there at one time – when we want them but not there at another time when we don ’ t. We want different things at different times. For example, I would like a tiny umbrella in my bag and a sufﬁciently big umbrella when it is raining and small again when not raining. I would like no protection systems round me when driving my car in normal conditions but would like airbags etc. to appear when I need them in an accident. I would like the centre of town suitably equipped for drunken clubbers when they emerge from pubs and nightclubs – but nothing unnecessary there in the daytime. TRIZ helps us think of solutions to understand how to create or locate systems to give us what we want. All the ways of overcoming Physical Contradictions are in the 40 Principles – the list of the Inventive Principles help us create systems which give us different things at different times. This includes Principles 29 Pneumatics and Hydraulics which is used in the imaginary solution below for an umbrella.
40 Principles Solve All Contradictions
Both physical and technical contradictions can be solved with the 40 Inventive Principles but the two routes to locating the relevant principles are very different. There is the very technical looking Contradiction Matrix for solving technical contradictions and there are the powerful Separation Principles for understanding and solving the different types of Physical Contradictions; each Separation Principle offers a selection of the 40 Principles which help solve or guide us to solution concepts to overcome particular physical contradictions.
The Contradiction Matrix is only for solving Technical Contradictions and shows which of the 40 Principles solve a particular technical contradiction but offers no solutions for Physical Contradictions – shown as the blank green diagonal boxes.
the high resolution contraddiction matrix can be found at "Appendice D"
Focusing on the technical contraddiction, each matrix axis is made up of 39 Technical Parameters which were uncovered by studying patents to identify these 39 most widely used and important characteristics of technical systems. They range from simple to complex features and functions, and between them can describe any engineering contradiction.
while the full described list can be found in "Appendice B"
Understanding the 39 Technical Parameters
As already said, The Contradiction Matrix is for situations when we have two apparently dependent or linked features and a solution improvement to the system means one needs changing or improving. When we improve or change a parameter (such as strength) then another linked parameter such as weight may get worse . The Worsening Parameter ( = extra weight) is the output we get as a consequence of changing or improving the other parameter (more strength).
We select on the vertical axis of the Contradiction Matrix the parameter we want to change or improve and identify the other Technical Parameter on the horizontal axis, which is linked and consequently gets worse. We can express this contradiction as a simple graph, which typically takes this form:
As we try to improve one parameter (strength) the other (weight) becomes worse, and vice - versa. It would appear that we are constrained to remain on the blue curve, which deﬁnes the set of possible compromise solutions available to us. What we would like to be able to do is to move off the blue compromise curve to a more ideal solution, i.e. in the direction shown by the green arrow. To achieve this we need to ﬁnd a way of breaking the link between the two parameters by solving the contradiction.
The beginning of the list of 39 Technical Parameters describes simple inputs (rows) or outputs (column) such as weight, length, area, volumes and shape for example.
Some deﬁnitions of Technical Parameters:
1. Weight of a Moving Object = The mass of the object, in a gravitational ﬁeld. The force that the body exerts on its support or suspension.
The deﬁnition of moving = Objects which can easily change position in space, either on their own, or as a result of external forces. Vehicles and objects designed to be portable are the basic members of this class. Towards the end of the list of the 39 Technical Parameters they become a little more complex and include inputs and outputs such as speed, forces, loads, stresses, pressures, use of energy, stability, duration of action, temperature, brightness, use of energy, power, reliability, convenience of use, repairability, adaptability, accuracy of measurement, accuracy of manufacture, manufacturability, productivity and level of automation. 39. Productivity = The number of functions or operations performed by a system per unit time. The time for a unit function or operation. The output per unit time, or the cost per unit output. The list also includes clearly identiﬁable harms (outputs we don’ t usually want) such as device complexity, waste of energy, waste of substance, loss of information, waste of time, control complexity and other harmful outputs. When using the matrix regularly, familiarity with the 39 Technical Parameters builds over time. It is worth looking at and learning (if possible) the meanings of all the 39 Technical Parameters, so when problem solving with the matrix, time is not wasted looking up meanings. This makes us more effective as valuable fast - thinking time is often needed when problem solving – if we don ’ t have to hesitate to check unfamiliar terms our brains keep moving and working in powerful creative mode.
TRIZ for Engineers: Enabling Inventive Problem Solving, First Edition. Karen Gadd.
© 2011 John Wiley & Sons, Ltd. Published 2011 by John Wiley & Sons, Ltd. ISBN: 978-0-470-74188-7