USING PHYSICAL MODELS in DESIGN

In the conceptual phase of designing consumer durables, important decisions are made for the investment and the extent of downstream efforts and activities. These decisions are important for the overall costs of a product and finally for the success of the product. Although, virtual concept modeling is available, the application of physical models can be justified by the fact that these models supply a base for communication, support and improvement of the creativity of a designer. In current rapid prototyping, the focus is on physical proof-of-concept models and going towards rapid fabrication. Physical models in the conceptual design stage are, due to the nature of conceptualization, different from those models, which are applied during the detailing stage of design. Some reasons for this are vagueness and incompleteness of product models, and different model usage and design. In this paper an inquiry among Dutch designers explores that statement. The first part of the inquiry showed that physical models in the conceptual stage of design are different from those applied in the detailing stage of design. All designers recognized that. The second part of the inquiry explores in what way they are different. Our study brings forward that a better understanding has to be achieved in terms of using physical concept models supporting conceptual design. Various applications for conceptual models are possible such as shape verification, communication, presentation, and functional testing. Each model will be tailored optimal for that usage and categories of models are recognized. New dedicated prototyping technologies are needed to acquire the best performance. The process needs support from a combination of tools, like natural geometry input, useful vague geometry representations, representation translators towards accepted CAD formats. When these facilities are available the input for rapid prototyping is possible. However, for a feasible implementation there are also requirements for the rapid prototyping process in terms of turn-around time, cost, process innovation and flexibility. The conditions for a feasible rapid prototyping process are discussed. Introduction A design process is a multi focal and complex process. The designer with his abilities and experience plays an important active role in that process. For his purpose he can rely on methodologies, supporting tools, company procedures and culture, and accessible information in any form. The design process will depend on the fact whether the design task is to redesign a product, or to extend a family of products or to develop a completely newly product. The complexity of the design process is influenced by the complexity in function and structure, and is demonstrated by the enormous amount of related papers. A substantial part of the papers are focussed on the development of supporting tools. Subjects like what, how and when to support the activities of the designer are discussed. Due to the individual abilities, flavor and qualities, diversification, functionality and complexity of products it is impossible to create one single solution or method for design tasks. In this paper the authors will explore the optimal usage of physical models in conceptual and detailing design. Physical models, produced by rapid prototyping technology, to support detailing design are commonly accepted and applied. It is also recognizable that physical models, which are realized by rapid prototyping in a conceptual design stage, are very scarce and almost nonexistent. Reasons are the vague geometry and the nature of the conceptual design stage. In design, models are produced to answer specific designers' questions [1]. When the conceptual model provides the answer to that question and the analysis is completed the model is wasted and the remaining value is maybe a capture of a part of the design process or the procedure. In order to minimize the effort of fabrication, in general a model must be created to meet as close as possible the necessary requirements. The conceptual model must be tailored for that purpose. In the conceptual design stage the sequence of ideas, thoughts, possibilities and challenges can change rapidly in time. Moreover the problem solving process can be characterized as being aspect oriented. It is in these circumstances very useful to produce physical models within a short period of time to assure a Company Design Bureau Activities