The central notion of TRIZ is that of a technical system and a Theory of Evolution of Technical and General Systems (TTS) provides a frame for reasonable justifications concerning the appropriate use of TRIZ tools. The TRIZ laws of evolution of technical systems are more than mere trends (as claimed in the recent MATRIZ standard book on the topic) - at least if trend is coined as in fashion or wheather trend - but (at least) best practices extracted from huge engineering experience that could be disregarded, but this would not be an intelligible action.
One of the discussion point is the question of the scope of application of these laws, since most of them are extracted from life lines as in (Altshuller 1979) and thus from practices of reusable technical systems that appear in a greater variety of similar realisations. This does not cover large technical systems (plants, software frameworks etc.) since those are unique specimen not designed for reuse even if standard components are used to compile them.
This raises the problem of a sound definition of the notion of a system and the foundation of a systems science.
Alexander Bogdanov: A system is a set of elements or relations that are naturally connected with each other into a single whole, which has a property that is absent in individual elements or in their unorganized aggregates (integrative property).
(Source: https://en.wikipedia.org/wiki/Systems_theory)
A system is a cohesive group of interrelated and interdependent parts which can be natural or human-made. Every system is
Changing one part of a system may affect other parts or the whole system. It may be possible to predict these changes in patterns of behavior. For systems that learn and adapt, the growth and the degree of adaptation depend upon how well the system is engaged with its environment. Some systems support other systems, maintaining the other system to prevent failure. The goals of systems theory are to model a system’s dynamics, constraints, conditions, and to elucidate principles (such as purpose, measure, methods, tools) that can be discerned and applied to other systems at every level of nesting, and in a wide range of fields for achieving optimized equifinality.
(Source: https://en.wikipedia.org/wiki/Russell_L._Ackoff)
Any human-created systems can be characterized as “purposeful system” when its “members are also purposeful individuals who intentionally and collectively formulate objectives and are parts of larger purposeful systems”. Other characteristics are:
Darrell Mann (2019). Systematic innovation in complex environments. In: Online Proceedings of the TRIZ Summit 2019 Minsk.