A little tricky electrical circuit problem in the “Su-Field: An Educational Example…” article (TRIZ Journal, Jan. 2006) is misused by the authors of the article to justify use of TRIZ. The example is actually based on a word game: the problem of distinguishing between two circuits INCORRECTLY states that these circuits “are equivalent”. This is an intentionally misleading verbiage. The correct statement should be that they are ELECTRICALLY EQUIVALENT.
As I was reading the article I realized this mistake on the forth paragraph of the problem definition: “mathematical proof that these circuits indeed are equivalent”. Mathematics can only prove that they are electrically equivalent, which means they present the same electrical effects. My immediate response was: what other – non-electrical – effects they present? The first answer coming to mind, since we are talking about electricity, is THERMAL effects… and the problem has been solved in that very moment.
I didn’t know that this is one of the solutions in the article, and continued reading it. However, since it appears to be a fake problem by then, all the blurb about “psychological inertia”, “intensifying restrictions”, eliminating “technical jargon”, “two substances”, “fields” – all the TRIZ jargon – looks completely meaningless. The conclusion especially looks artificial.
This is a word trick, not a technical problem, and as such has nothing to do with TRIZ. Like other word tricks we know from school, this one can be useful to train one’s mind in thinking, but using TRIZ to solve it is absolutely inappropriate and misleading.
Y. Karasik called my attention to the couple of other misuses of this example in the article. First, the authors make impression that the problem was proposed in the IEEE magazine for solution, and it was solved using TRIZ, probably by the authors themselves. However, the web search shows that this is just an exercise, which routinely gets solved without TRIZ. See for example Circuit Design Contest for College Students, problem 2.
Second, the authors refer to Su-Field analysis and specifically to the "Inventive Standard 1-1-1" as the TRIZ tools applied.
However, Su-Field analysis requires INTRODUCTION of the missing element. The standard 1-1-1 says:
If there is an object which is not easy to change as required, and the conditions do not contain any limitations on the introduction of substances and fields, the problem is to be solved by synthesizing a SFM: the object is subjected to the action of a physical field which produces the necessary change in the object. The missing elements being introduced accordingly.
The authors misapply the Su-Field analysis and the Inventive Standard: no field is introduced because it is already present! This example is wrong even as a retrospective study.