Difficulty in locating existing information in order to reuse it constitutes a major challenge to productivity. The use of PLM systems (Product Lifecycle Management) aims in particular to reduce the time and cost of developing a product by facilitating the re-use of existing parts or related information (process plans, tools, FEM, estimates, etc.). When information is alphanumerical, using search engines, such as those made popular on the internet, is efficient. However, a significant portion of information used in engineering rests within CAD (Computer Aided Design) models, making such search tools irrelevant. To aid in the re-use of information, two problems must be resolved: it is first necessary to be able to locate similar parts in the electronic database of the company, and then be able to systematically identify their differences. This article presents some of the results from our work on part, product and process data mining (P3DM). It focuses on tools developed to search similar 3D geometric models and to identify their differences. The PartFinder application locates similar parts by comparing signatures extracted from their solid representations. The 3DComparator aims to identify the differences in terms of Form and Fit between the identified parts. In both cases, the recommended approach is independent of the CAD system, and can also deal with parts represented by IGES or STEP files. Moreover, the approach does not require that the parts occupy the same position and have the same orientation in space. These two points, CAD and position independence, are the main benefits of our approach compared to other existing applications. Lastly, if the comparison takes place between two evolutions of the same geometrical representation of a part, a third tool allows the comparison of the specification trees. The SpecComparator is also presented briefly. An example based on industrial data illustrates the benefit that could be generated.
