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Theory of Inventive Problem Solving (TRIZ) 307

9.5 Technical Contradiction Elimination—
Inventive Principles
Genrich Altshuller analyzed more than 40,000 patents and identified
about 1250 typical technical contradictions. These contradictions are
further expressed into a matrix of 39
39 “engineering parameters.”
To resolve these contradictions, Altshuller compiled 40 principles.
Each of the 40 principles contains a few subprinciples, totaling up to
86 subprinciples.
It should be noted that the 40 principles are formulated in a general
way. If, for example, the contradiction table recommends principle 30,
“flexible shell and thin films,” the solution of the problem relates some-
how to change the degree of flexibility or adaptability of a technical
system being modified.
The contradiction table (see chapter appendix) and the 40 principles
do not offer a direct solution to the problem; they only suggest the most
promising directions for searching for a solution. To solve the problem,
one has to interpret these suggestions and find a way to apply them to
a particular situation.
Usually people solve problems by analogical thinking. We try to
relate the problem confronting us to some familiar standard class of
problems (analogs) for which a solution exists. If we draw on the
right analog, we arrive at a useful solution. Our knowledge of anal-
ogous problems is the result of educational, professional, and life
experiences.
What if we encounter a problem analogous to the one we have
never faced? This obvious question reveals the shortcomings of our
standard approach to invention problems. So, the contradiction table
and 40 principles offer us clues to the solution of the problems with
which we are not familiar. When using the contradiction table and
40 principles, following this simple procedure will be helpful:
1. Decide which attribute has to be improved, and use one of the 39
parameters in the contradiction table to standardize or model this
attribute.
2. Answer the following questions:
a. How can this attribute be improved using the conventional
means?
b. Which attribute would be deteriorated if conventional means
were used?
3. Select an attribute in the contradiction table (see chapter appen-
dix) corresponding to step 2b.
4. Using the contradiction table, identify the principles in the inter-
section of the row (attributes improved) and column (attribute dete-
riorated) for overcoming the technical contradiction.