A NEW LIFE CYCLE MODEL FOR THE CONCEPTUAL DESIGN PROCESS
Life cycle considerations and design options are hardly quantitatively taken into consideration during the conceptual design phase. In order to provide the type of information required to make decisions based on scientific arguments, a general life cycle model is gradually introduced throughout this research. This presentation tries to give an overall picture of our model. Some other articles have developed the proposals made in this article more thoroughly [Coatam!a et al., 2004]. At first the general problematic is introduced. The three main issues which guide this research are respectively: the desire to reduce the ambiguity at the modelling level, the importance of unirying and minimizing the way of describing a design concept and finally the importance of providing repeatability and measurability. The key idea or this research consists of using dimensional analysis. At first, our research method consists of showing that on the mathematical point of view dimensional analysis can help in attaining the ideal topological space called Metric space as described in the general design theory (GDT) [Yoshikawa, 1981]. We show how the basic semantic of functions and attributes can be described in agreement with this theory. In thc third section, we present the general structure of our design model. In this structure we have decided to use existing tools but we have improved those tools by the introduction of two fundamental proposals: dcsign is seen as a "Russian dolls" system of thermodynamic structures called Open systems [Glansdorff et aI.., 197f] and classification is systematically used in order to progress in direction of the topological space called metric space. The progressive transformation of the semantic description is briefly explained using the example or a pressure regulator. A more precise description is available in [Coatanca et aI., 2004], The fourth section is devoted to the analysis of the system or based and derived quantities necessary to build a consistent framework. In the fifth section, some other aspects related to the progressive modelling of the pressure regulator are studied through the viewpoint of the developed framework.