An approach to machine tools structure selection for wooden product machining based on evidence networks

During the product development phase, especially in the case of innovative products, designers used to face the unpleasant situation to be obliged to take decisions under conditions which are characterized by a relevant degree of uncertainty and even contradiction. This situation is quite frequent in the very early phases of the design process, where a large part of external conditions are not fully defined. It is also the case of a designer of machine tools. As methodological response able to fill this informative gap, the present paper presents a way for using "evidential systems" as supporting tool for designers. These tools represent a sort of expert systems in which knowledge is represented and processed by the function of the Belief Function Theory (also called Dempster-Shafer Theory). In particular, beyond a deep description of this methodology, the paper is focused on the conceptual design of a machine tool, i.e. determination of the best structure of machining center in the phase of conceptual design for a predefined group of wooden parts that are being machined on them.