This overpriced book [40 Principles: Triz Keys to Technical Innovation] contains a set of 40 design strategies for inventing. It is a summation of engineering design principles devised by a Soviet patent examiner in the 1960s who extracted these principles from a study of 200,000 patents. This guy, Altshuller, says that the 10% most innovative patents would use one of these 40 strategies for their novel solutions. Altshuller then went on to construct a system to help engineers consider these elemental strategies for the problems they were working on. His system is called TRIZ, and it has a cult following among process engineers.