The problem of assembling products, raw materials and semi-finished products has several nuances according to the field in which the products are placed and the aim of the aggregation process. Assembling financial products in a homogeneous way, assembling investments, assembling products to be marketed: these are some current examples in the complex network of today's economic and financial systems.
The homogeneity of the products, raw materials and semi-finished products is normally based on those characteristics required from them. Hence the increasing importance of the way in which the characteristics are assigned to the products. In the model we put forward, a fuzzy sub-set is determined for each material. Its referential is given by the set of characteristics or properties. The proper analysis of these fuzzy sub-sets must enable us to determine the adequacy of each materials or group of materials to the goal we wish to obtain.
Several patterns have been put forward with the aim of solving this question. In our view, however, any of them is suitable to obtain results in a context with a high degree of uncertainty, such as the one in which we are nowadays. The theory of the clans is the mainstay of the model we develop. In the near past, this theory was very useful for the informative treatment of files.
After establishing a fuzzy relationship which links the products, raw materials and semi-finished products and their qualities and with the help of a threshold vector which measures the relative importance of each characteristic, a Boolean matrix is obtained. This matrix will be the basis of the later development of the model. In the model, the clan is engendered starting from the notion of "family", which becomes the source element.
The clan enables an in-depth analysis of the materials, since it provides a differentiation group by group (the sub-sets making up the group) according to the characteristics or properties that one material and/or the other have, the characteristics are present in the members of the group. Thus, it is possible not only to know the products, raw materials and semi-finished products one must have recourse to, when it is necessary to cover some characteristics, but, in addition, it is also possible to know the number of materials in the group having that particular characteristic.