The major limitation of horizontal CAD systems used for mechanical drawing, such as AutoCAD and BricsCAD, is the impossibility of structuring the drawing hierarchically:

  • The layers are all at the same hierarchical level, i.e. it is not possible to define parents with children.
  • Blocks, on the other hand, can have a sort of hierarchy among them, but they are extremely cumbersome to manage.


Using parts offers the following advantages:

  • You can select conveniently an entire part, together with any subparts, by indicating even just one of its elements.
  • The parts can be stored in a file and later loaded from that file through the dedicated TOP commands. This technique makes it possible to create custom libraries. With the use of the integration with the PDM Data & Drawings the search for the various library drawings is greatly facilitated, since selections can be made based on attributes.
  • By creating a drawing divided into parts it is possible to have several people work on the individual parts that compose it, and assemble the whole drawing at the end.
  • By creating a drawing divided into parts it is possible to simplify its display, and therefore also the approach during drawing, by acting on the visibility of the parts.
  • The use of parts facilitates the management of the drawing and of the editing commands, thanks to the locking of parts at hierarchical levels higher than the current one, and thanks to the possibility of locking arbitrarily certain parts in order to avoid accidental modification.
  • The bill of materials of the drawing is created automatically: it is the entire parts tree. However, it is always possible to exclude some parts from the bill of materials.
  • The ballooning is done by selecting a part; then, when the table is created, the attributes of the previously ballooned parts are read automatically.
  • The compilation of the title block is done automatically by "reading" the attributes of the TOP part (i.e. the main part).