Many SMEs are manufacturing sub-contractors, leaving their purchaser manage the design phase. Even those using CAD systems do it in a very basic way. They face technical and methodological problems when they try to evolve to functional design which is mandatory in the globalized world, for instance to use numerical simulation before manufacturing. Simulation is mainly used to verify the specification, all along the design process. Many SMEs follow well known stages: Modelling the object using CAD system, simulation under given condition of the behaviour of the model, modification of the CAD model. Some limitations or drawbacks of this kind of process are obvious: the designer does not manage the multi-criteria aspects of the problem and by using the constructive approach of CAD systems, he cannot express the overall objectives.
In order to be more efficient, intensive simulations, based on trade knowledge, should be done before the design itself.
After an introduction presenting the context of the research, we detail in chapter 2 the evolution of the process from the traditional process to the XFD (X For Design) one.
In order to verify the interest of XFD, we have chosen to process industrial, mainly on industrial (SMEs) cases. This work has been then a central work of the research centre DINCCS theme for last five years as an inductive research. About fifty industrial cases have been studied. About twenty of them are significant for the object of this paper.
In order to illustrate the diversity of the industrial cases we detail (not technically) some examples. We present some important results, considering three cases, based on the technology point of view:
- The integration in a specific tool of the numerical simulation and CAD system.
- The use of numerical optimization before design
- The specific use of trade knowledge in a dedicated system
Then, we discuss the strategy point of view, illustrated by six main cases.
The industrial examples confirm that this new approach can provide a quantifiable competitive advantage for most manufacturing SMEs. This is very important for SMEs, particularly manufacturing ones. Using numerical simulation (optimization) intensively, before defining the CAD model, they can get unexpected gains (mass, quality, better use of the means of manufacture).