The development of complex products is based on the exploitation of powerful Digital Mock-Up (DMU). Indeed, the three-dimensional geometric modeling of mechanical components constitutes an indispensable activity for the design. Computer-aided design (CAD) tools allow faithful and accurate representation of the product shape. This shape is the basic support used in the design phase and subsequent processes.

In order to satisfy customer needs and ensure the best ratio price-quality, the geometric definition evolves, i.e., changes are made to the product shape according the product life cycle. Different models used and maintained by the specialists must also evolve in a coherent way. In fact, this evolution impacts the technical data specific to each discipline, as manufacturing , calculation and assembly models.

Thus, for each contribution of a multidisciplinary participant, the geometric model data accumulate. This conducts industrial companies to retain and reuse data corresponding to reliable and approved products. The company knowledge and experience are capitalized as well as skills are better exploited.

The proposed work in this paper proposes a tool for comparing geometric models. The comparison is founded on two main steps. The first step constitute an aggregation and filtering step. The studied model is selected as a reference one. Similar models are automatically determined according to the geometric information of CAD entities. The second step is based on geometric entity characteristic as comparison criterion to refine results. The entity identity comprises the Boundary Representation (B-Rep) model.

The proposed tool is required a comparison between the studied model and the library of models already realized and approved by the company as well as to choose the most similar product. This choice allows to take advantage of acquired experiences as cost of production, problems encountered, etc. Several services will benefit from the difference characterization based on geometric information: the engineering to standardize the components, using similar models for calculation or manufacturing, etc. Otherwise, the proposed tool allows to reduce production time that decreases product cost.