# Formalization of the notion of technical systems evolution (Part 3):Evolution of distributions and the Altshuller evolutionary series

### Y. B. Karasik, Thoughts Guiding Systems Corp., Ottawa, Canada. e-mail:karasik@sympatico.ca

Most TRIZ patterns of evolution involve not evolutionary series of technical systems [1, 2] but evolutionary series of distributions of technical systems. Consider, for example, such trend of aircrafts' evolution as "from bi-planes to mono-planes", which was typical in the 1930s. What did it mean ? It did not mean that all bi-planes were followed by mono-planes. It only meant that bi-planes gradually gave way to mono-planes. This trend was not about evolutionary series of technical systems but about evolutionary series of their distributions. Up until some point in time bi-planes were in the majority, then they became in the minority. Distributions evolved in this case, not necessarily all bi-planes were followed by some mono-planes.

Most, if not all, TRIZ patterns of technical systems evolution are about evolution of their distributions rather than technical systems themselves. Consider, for example, another trend: from propeller driven aircrafts to jet driven aircrafts. It is not that both types of aircarfts belonged to the same evolutionary series as defined in [1]. This trend is also about distributions: propeller driven aircafts were the only types of aircrafts in the beginning, then jets appeared but were in the minority, and then they became in the majority. Distributions evolved here (along with some aircrafts, though).

Analysis of Altshuller's examples of evolution of technical systems suggests that by evolution he meant change of the system representing the majority. This can be formalized as follows:

Definition: Let DS,C(t) be a distribution of systems S according to a criteria C at a moment t. (For example, if S are aircrafts and C is the number of wings, then DS,C(t) is the distribution of planes according to the number of their wings at a moment t.)
Let SCmajority (t) be the majority of systems S at a moment t according to the distribution DS,C(t).
Then the Altshuller evolutionary series of the first kind is a series {SCmajority (ti)}i=1N.
The Altshuller evolutionary series of the second kind is a series {si}i=1N, where si ∈ SCmajority (ti).

R E F E R E N C E S:

1. Y. B. Karasik, "Formalization of the Notion of Evolution of Technical Systems", Anti TRIZ-journal, Vol. 7, No. 8, September, 2008.

2. Y. B. Karasik, "Formalization of the Notion of Evolution of Technical Systems (Part 2): Various Types of Evolutionary Series", Anti TRIZ-journal, Vol. 7, No. 9, October, 2008.