In an updated study conducted by Mann (www.triz-journal.com/archives/
2004/04/01.pdf), use frequency has changed. The degree to which their frequency/less frequency of use if also highlighted in terms of how far they have advanced up the list (Again, remember that these numbers refer to frequency of use, not the numbers of the principles). Reasons for these changes will be discussed next (Table 9.3).
Before we look at the principles that have increased or decreased in the fre- quency of use, look at which parameter is still #1, after 60 years! Parameter change—why? It is because the change in a system’s basic parameters usually causes fundamental change in properties and/or a large energy change, both of which are potential source of significant change to a system or product.
Let’s consider some possible reasons for the increased use of certain principles.