How Problems Are Solved in TRIZ Literature: The Need for Alternative Techniques to Individuate the Most Suitable Inventive Principles

TRIZ capability of individuating appropriate instruments for specific problems is often challenged. Although each TRIZ user tends to prefer certain tools over others, Inventive Principles undoubtedly represent the most popular technique. Consequently, a more appropriate guidance to select the most promising ones for a given problem would result in a clear advantage for designers. The Contradiction Matrix should support this process, but its reliability is often questioned. In this framework, the authors have analysed problems solved with TRIZ and described in TRIZ-related literature. This choice reflects the need to pay attention to case studies really faced with TRIZ instead of being reconstructed from other examples. The analysis includes 42 case studies from acknowledged TRIZ sources. Unfortunately, literature about problems solved with TRIZ is highly dispersed and the creation of a greater sample would have required considerable efforts. The following results emerged from the analysis. The Contradiction Matrix would have supported the determination of the described solutions in very few cases, namely eight, which confirms its limited reliability. A small number of Inventive Principles addresses the majority of the illustrated solutions; for instance, four of them are sufficient to solve almost 60% of the presented problems. Additional criteria have been used to classify conflicting parameters (more specifically a characterization in terms of Useful Functions, Undesired Effects and Resources), but their relationship with employed Inventive Principles seems quite random. The paper wills to open up a discussion about this presumable randomness of Inventive Principles and the possible measures to tackle the problem.