Recently I cruised the Mediterranean and visited Istanbul. This visit inspired many thoughts. One of them was the realization that employing TRIZ concept of S-curve results in the dead-end branches of evolution. Here is why.
Consider, for example, evolution of catapults. It stagnated back in Roman times. This was the reason of why Constantinople stood for almost 1000 years after that. Its walls were designed after catapults stagnated and were built to withstand the impacts from the biggest stones that catapults could throw.
According to the TRIZ concept of S-curve, to throw a bigger stone than catapults were capable of throwing, transition to another system had to take place. The new system had to throw stones employing another principle of operation than catapult.
Such a new system was proposed by a person named Orban to the Turkish Sultan Mehmet II. It was a huge cannon capable of throwing stones weighing as much as 750kg at a distance of as far as 2 km. And these guns obliterated the hitherto impregnable walls of Constantinople and it fell to turks.
Turks continued building huge guns shooting granite cannonballs of almost 1m in diameter for long time after the conquest of Constantinople. These huge guns and their huge stone cannonballs frightened Europe for long. But it was a dead-end branch of guns evolution.
A proper system, which should had replaced catapults, had to be not a gigantic gun that shot gigantic stone cannonballs but a relatively small gun that shot relatively small iron cannonballs filled with explosives. They would had smashed the Constantinople walls more efficiently. But TRIZ concept of S-curve does not suggest such transitions. It suggests a transition to a new system that does the old job (e.g. hurling stones):
One can argue that small cannons firing small cannonballs filled with explosives were the next step in the evolution of cannons after huge cannons firing huge stone cannonballs reached the limits of their improvement. But it is not the case. Firstly, cannons shooting shells cannot even be put on this graph as their performance is not measured by the kinetic energy of projectile. Secondly, cannons shooting shells appeared almost simultaneously with cannons shooting solid shots [1, 2]. The quality of shells did not improve for long time, though.
TRIZ concept of S-curve aims at replacing a system which reached a certain limit of improvement by a new system without this limit that does the same job. As the above example shows, such new systems turn out to be the dead-end branches of evolution. Even though they may help achieve a hitherto unattainable goal.