Identification of sensory variables towards the integration of user requirements into preliminary design

Industrial designers have to design products that meet user requirements. User requirements are usually used as validation elements at the end of the product design process. Yet, at this stage in the product design process, many decisions have already been made. Decisions made by designers in the preliminary design phase account for 70% of total product development costs. Therefore, iterating a design process is very expensive. The objective of the approach presented in this paper is to integrate user requirements at the beginning of preliminary design. The general object of the approach is to find links between a sensory characterisation and a functional characterisation of a product. Using such links, designers will be able to evaluate the influence of design decisions on user sensations. We propose to identify a product's functionalities. On the one hand, we define and quantify sensory variables relating to a product's functionalities and on the other hand we identify and quantify criteria variables and design variables. Then we search for relations between sensory variables (SVs) and criteria variables (CV)/design variables (DV). Methodologies and process used are presented in this paper. The present approach is applied to the parabolic ski in basic turn. With this example, we study somesthesia which is the sensations set perceived within muscles and ligaments. We obtain links between SVs and DV. We can integrate user requirements into preliminary design.