One of TRIZ mechanisms of solving problem is finding and resolution of contradiction. However, problem can be expressed in various contradictions. So, to solve it it is not enough to find just some contradiction from which the problem follows because it may turn out to be unresolvable. It is imperative to find such a contradiction which not only entails the problem but also can be resolved.
Consider the following problem. When spraying crops with crop protection products from an agricultural aircraft the higher the speed the higher the performance. But at the same time, the higher the speed the more chemicals fall outside the crops field, contaminating the adjacent territory. So we have a contradiction: aircraft's speed has to be slow so that not to contaminate the adjacent areas and has to be high so that to increase performance. This contradiction does not have a solution but it can be transformed into that, which has.
To this end we first assume that the speed is high. Then we ask why at a higher speed more chemicals fall outside the field. It is because the incoming airflow is stronger and disperses the liquid chemicals into smaller drops, which are more easily drifted farther from the field. Thus, we obtain a new contradiction: the chemicals have to be dispersed into smaller drops at a higher aircraft speed because they are liquid and have to be not dispersed into smaller drops so that not to contaminate the areas outside the field.
This contradiction also does not have a solution and has to be further transformed. We cannot make liquid chemicals to disperse and not to disperse into smaller drops. But we can make them not to disperse into drops at all if we make them not liquid. Thus, we obtain a new contradiction: the chemicals have to be liquid so that to cover crops and have to be not liquid so that not to be dispersed by the airflow.
This contradiction has a solution. It is obtained by separation of the contradictory requirements in space and time. The chemicals have to be not liquid when leaving the aircarft but have to be liquid when descending onto crops. Here is a solution: chemicals leave aircraft in small capsules, which also contain freon. The capsules warm up due to the friction against the air and freon vaporazies exploding them and releasing liquid chemicals. By the time capsules explode they are closer to the crops and the speed of the airflow is also much lower than when they left aircraft. Thus, they do not get dispersed into too small drops too high in the air. (see the USSR invention authorship certificate #534221).
The transformation of contradictions has been accomplished into 2 ways. First, being unable to resolve contradiction between X and not-X, we chose X. We then asked why X causes the unwanted effect. In this way we found that X causes the unwanted effect through Y: X actually causes Y, which causes the unwanted effect. Thanks to it, we transferred contradiction from X onto Y. Being still unable to resolve the contradiction between Y and not-Y, we decided that neither Y nor not-Y should take place. We then asked what precludes X from not causing either Y or not-Y. We found that it was Z that had property P. As a result we transferred contradiction from Y onto Z: Z had to have property P and had to not have it. This contradiction turned out to be resolvable.
These methods of contradictions transformation are part of a bigger theory under development.