Model based definition

Model Based Definition is a new strategy of product lifecycle management in which the CAD models (Computer aided design) change from simple models with only the geometric data to extensive information sources containing all product manufacturing information (Alemanni, Destefanis, & Vezzetti, 2010).

Model Based Definition is the use of 3D models in 3D CAD software, to define individual components and product assemblies. The Model Based Definition technology can be considered as a new generation for product definition methods. The modern 3D CAD systems make it possible to insert technical information such as geometric dimensions, tolerances, material specifications, 3D annotation and surface finishing into the 3D digital dataset. The 3D digital dataset contains enough information to produce and inspect the product without the previously used 2D technical drawings (Zhu et al., 2016).

In the traditional industrial method, the 3D CAD model describes the geometric information of the product and the 2D technical drawings define the dimensions, tolerance and process information. When using Model Based Definition technology, the 3D model becomes the basis for product definition, engineering of product processes, production planning and quality inspection. This avoids the time-consuming process of the traditional method based on engineering drawings (Zhu et al., 2016).

The objectives of Model Based Definition technology are:

  1. Suppression of unnecessary documents and drawings;
  2. Better data consistency;
  3. Better product/process virtualization;
  4. Better support for all CAx technologies.


The importance of Model Based Definition for Feature Based Machining

Because the 3D CAD model is based on Model Based Definition technology, the 3D CAD model serves as the only document, containing all relevant product and process data, for the most important engineer/production phases. This keeps all data constant throughout the entire process. As a result, CAx technologies offer a more extensive set of data, enabling better integration and automatically performing tasks within the CAM system (Feature Based Machining)

When using Model Based Definition as the basis of Feature Based Machining the following benefits are achieved (Zhu et al., 2016):

  1. Shortening the manufacturing cycle;
  2. Improving the quality of the product;
  3. Lowering production costs;
  4. Increasing the competitiveness of the market.


[1] Alemanni, M., Destefanis, F., & Vezzetti, E. (2010). Model-based definition design in the product lifecycle management scenario. The International Journal of Advanced Manufacturing Technology, 52(1–4), 1–14.

[2] Zhu, W., Bricogne, M., Durupt, A., Remy, S., Li, B., & Eynard, B. (2016). Implementations of Model Based Definition and Product Lifecycle Management Technologies: a Case Study in Chinese Aeronautical Industry. IFAC-PapersOnLine, 49(12), 485–490.

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