- To archive the geometric form of the design.
- To communicate ideas between designers and between the designers and manufacturing personnel.
- To act as an analysis tool. Often, missing dimensions and tolerances are calculated on the drawing as it is developed.
- To simulate (visualize) the design.
- To serve as a completeness checker. As sketches or other drawings are being made, the details left to be designed become apparent to the designer. This, in effect, helps establish an agenda of design tasks left to accomplish.
- To act as an extension of the designer's short term memory. Designers often unconsciously make sketches to help them remember ideas that they might otherwise forget.
- One of the earliest studies, Larkin and Simon’s "Why a Picture is (Sometimes) Worth Ten Thousand Words" argues that a diagram is a representation created to externalize and visualize problems .