What is System in TRIZ ?

Y. B. Karasik,
Thoughts Guiding Systems Corp.,
Ottawa, Canada.

Various TRIZ rules and "laws" use terms system and super-system without defining them. It might appear that technical system is a group of objects that together perform one or more functions.1 But in TRIZ system is often a group of accomplices to a failure. For example, Innovation Algorithm ARIZ-71 has step 3.1, which reads:

Step 3.1: A system is given that consists of __________________________________________________
                                            (List all elements involved in the undesired effect)

In view of this fact one could try and modify the definition of technical system as follows:

But what is about systems that do the both ? For example, the group of objects called automobile both performs the function of transportation and generates multiple undesired effects in the environment. Thus, we arrive at the new definition:

But my sight fell on the ladder lying in the basement of my house. Is it a technical system or not ? - I wondered. It is a group of objects. But while the ladder is not being used this group of objects neither performs any function nor generates any undesired effect (except occupying space in my basement). Nevertheless it has a purpose, which it was both designed and assembled for. Would it be, therefore, more prudent to further modify the definition as follows:

Consider, for example, a ratchet socket. Its purpose is to grasp a nut. i.e. not to allow it to rotate with respect to the socket while a momentum (of up to some threshold) is applied to it. This purpose cannot be realized until some other object (ratchet) starts applying a momentum to it. Thus, we come to a conclusion, that technical system may not be able to realize its purpose until it teams up with other objects and becomes a portion of a bigger system3. This naturally brings us to the need of expanding our analysis to include into it super-systems.

Likewise with system, TRIZ also inverts the common notion of super-system. In Webster super-system is defined as a system consisting of other systems. But in TRIZ super-system is a system, which the given system belongs to. The difference is huge. TRIZ definition tacitly implies that any system has a super-system, whereas theory of systems does not claim that. Moreover, as we just saw, the idle technical systems often do not have super-systems.

Consider, for example, the afore-mentioned ladder. While lying idle, it does not have any super-system. But when I use it for painting the ceiling, it has. The immediate super-system is ladder + I mounted on it. A further super-system is ladder + I on it + brush in my hand. Etc.

Thus, we come to a conclusion that super-systems of purely artificial technical system may not be purely artificial but include human beings. Artificial is not a synonym of technical, and artificial and technical systems are not the same. The TRIZ "trend" of diminishing the human involvement is related to super-systems of purely artificial technical systems.

F O O T N O T E S:

1Such a definition can be obtained from Webster by modifying its definition of (specific) biological systems as "groups of body organs that together perform one or more vital functions, e.g. digestive system".

2 It might appear that it suffices to say that "technical system is a group of objects that either have a purpose of performing some functions, or generate undesired effects, or do the both". It might appear that if a system actually performs some functions then this is its purpose and mentioning of actual performing is redundant here. However, there are systems, which happen to perform functions which they were not intended for, which purpose was different. That is why definition has to include both "purpose" and "actual performing".

3 One could claim that socket is not a technical system but rather a device on the ground that although it has a purpose it alone is unable to realize it; that here system is socket+ratchet+technician (because without a technician socket+ratchet also do not work). Such distinction between "technical systems" and "devices" would be illogical and would lead to inclusion of the entire universe into any technical system because without it a human being (the technician) is also unable to work.