Abstract : The main objective of this dissertation is the improvement of the analogue and mixed design flow, using reuse methodologies. Development and exploration methodologies for the IPbased library (Intellectual Property) are developped: definition and characterization of an analogue IP, creation and exploration of the IP-based library, reuse help for the designer. The demonstrator is a neuromimetic integrated circuit which fits the electrical activity of biological neurons. Those applications describe, with three examples, the efficiency and the flexibility of this methodology. A resizing methodology of CMOS analogue designs during a technological migration is also developed in this work.