In their groundbreaking 1959 article "Expulsion of the six-wings seraphim" G.S. Altshuller and R.B. Shapiro wrote: "eliminating contradictions is the foundation of machines' evolution". It was tacitly assumed that any technical contradiction can be resolved. But there are ones which cannot. For example, the golden rule of mechanics is one of such contradictions: you cannot win both in force and distance. Computers feature other types of unresolvable contradictions: you cannot win both in speed of computation and required memory (or in versatility of a computer/software and convenience of its use, etc).
It is true that such contradictions could be eventually eliminated by inventing a system that works using other physical principles. But what happens in between ? Don't systems evolve until new technical systems based on new physical principles emerge ?
Yes, they do. But their evolution leaves unresolvable technical contradictions pertinent to them intact. It is not that their evolution is not affected by such contradictions at all. On the contrary, unresolvable technical contradictions drive their evolution in a certain direction. This direction is multiplying trade-offs rather than creating one system where contradiction is resolved. 1
iPad is the latest example to it. Indeed, iPad is a trade-off between versatility of a computer and convenience of its use. This contradiction (which is pertinent to all computers) cannot be resolved. Therefore each computer represents a trade-off. For example, laptops can do more than iPads but less convenient at performing certain tasks.
The very fact that contradiction cannot be resolved causes proliferation of trade-offs. This is the main avenue of technological evolution in the absence of new physical principles which could help and resolve contradiction.
This result is a significant deviation from Altshuller's concept of technological evolution. His laws (such as evolution towards IFR through contradictions resolution, etc.) are the laws of converging whereas the main trend in technological evolution is diverging.
Accordingly, the current TRIZ has tools of problem solving but lacks tools of envisioning and conceptualizing new unexpected trade-offs that may have market success, such as iPad, for instance. However, they are startling trade-offs that are demanded most, not solutions that resolve contradictions. This is one of the reasons of why people stop using TRIZ after the initial enthusiasm following its learning wanes.
1 trade-off is a compromise between contradictory parameters of a system.