Definition des familles de produits a l'aide de la logique floue

In this thesis, the main contribution is concerned to the design of product families by applying fuzzy logic, in order to improve the decision making process. We consider that the formation of product families enables companies to offer a wide variety of products allowing the satisfaction of different types of customers into the target market, and avoiding a costly diversification by designing customized products for each customer. Fuzzy logic allows entering information provided in linguistic terms familiarly expressed by the people. That is to say, it allows considering more consistent information close to the expressed by customers and it is not limited to handle binary variables as the Boolean logic. Fuzzy logic through the formulation of different membership functions can evaluate more answers of a variable instead of a just a "yes" or a "no".First, an improved fuzzy ranking procedure for decision making in product has been proposed to permit the evaluation of the fuzzy preference relations among several fuzzy numbers with different membership functions. This fuzzy ranking procedure has been supported by the definition of twenty-nine general cases, which is enough to consider all the possible situations between two normal fuzzy numbers. These general cases have been presented as a framework to facilitate the inclusion of other membership functions.Later, regarding the design of product families, different tools have been developed, implemented, and integrated into a global methodology to form families of products. These tools include: a ranking procedure for fuzzy decision-making in product design to compare different products, a method to select products based on the fuzzy preferences of the customers, an iterative method to configure products for specific customers, a method to configure different products to satisfy the different segments of the market, and finally the integration of all these tools in a global methodology for designing families of products by using fuzzy logic. This work contributes to the design of product families by enabling the handling of information in linguistic terms commonly used by the customers to express their preferences in relation to determined characteristics of certain products and services.In the last chapter of this thesis, some perspectives have been presented.After carrying out the literature review, regarding to the fuzzy logic and to the product family development. We concluded that the process of decision making is fundamental for the effectively formation of families of products, and that the fuzzy ranking is the basis of such process. In this work, various fuzzy logic-aided tools have been developed and applied aiming at achieving the main objective.