Abstract
Patent classifications are systematically used in patent analysis for a number of purposes. Existing classifications not only shape the administrative activities of recording and reporting and the search for prior art, but also create the backbone of the construction of science and technology indicators used in economic analysis, policy making, and business and competitive intelligence.Yet the current classification system of patents, despite significant and continuous efforts to update, suffers from a number of limitations. In particular, it fails to capture the full potential of inventions to cut across industrial boundaries, does not allow fine-grained technology intelligence, and misses almost entirely the opportunities for lateral vision.We suggest integrating existing schemes with a full scale functional classification, i. e., based on the main functions performed by a technology, rather than on the inventive solutions or their potential applications. The functional approach allows us to overcome most of the limits of traditional classification, due to the generality and abstraction of the representation of functions. In this chapter, we will first review the conceptual background of the functional approach in epistemology and analytical philosophy and illustrate its recent developments in engineering design, design theory, artificial intelligence, computational linguistics, and data mining. We then discuss three short case studies of the application of the methodology for the definition of patent sets, prior art analysis, and technology crossover identification and mapping.