Contradictions

Overview

Contradictions are parametric models of key problems identified during problem-identification stage of the project. In modern TRIZ, two types of contradictions are used:

The engineering contradiction involves two different parameters. It represents a situation where improving one parameter leads to the deterioration of another.

The physical contradiction, on the other hand, pertains to one parameter with two justified but conflicting requirements imposed on it.

Relation between the engineering and physical contradiction

Engineering and physical contradictions are directly related as both are formulated from IF-THEN-BUT format.

in the engineering contradiction, the improving parameter is placed in the line THEN, while the worsening parameter – in the line BUT;
the physical contradiction concerns the parameter from the line IF, while the contradictory demands can be found in the line THEN.

The physical contradiction can be formulated based on the engineering contradiction in the following steps:

formulate an engineering contradiction,
go to the line IF of the contradiction; the parameter/action/property mentioned in the line IF is the one around which the physical contradiction is formulated,
the line THEN of the engineering contradiction is the justification of one of the requirements of the physical contradiction;
the line BUT can prompt the justification of the other requirement (inverting the statement in the line BUT provides the justification).

To formulate the physical contradiction, creating an inverted (alternative) engineering contradiction beforehand can also be very helpful.

The conversion also works in the opposite direction. From each physical contradiction, two engineering contradictions can be derived: the basic and the inverted (alternative) one.

Resolving the contradictions

For both types of contradictions, the 40 inventive principles are the recommended models of solutions. However, the ways leading to the specific principles are different:

for the engineering contradiction, it is the contradiction matrix, also referred to as Altshuller matrix.
for the physical contradiction, it is the algorithm for resolving physical contradictions.

Aditionally, function-oriented search (FOS), database of scientific effects, and clone problems application can be used for physical contradiction.

Contradictions

Overview

Relation between the engineering and physical contradiction

Resolving the contradictions

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