Design rationale is often not recorded in mechanical engineering designs because it is not convenient to stop the design process to record every design decision that is made. Designing directly on the computer could assist the process of design rationale capture. At the very least a computer design tool could record all the changes made to a design over its lifetime.

Unfortunately, current computer-based design tools for mechanical engineers are not tailored to early stages of design. Most designers use pencil and paper at first, and input their design into CAD systems only after it is nearly complete. The tradeoff between the ease of drawing and the precision of a CAD tool is too great for engineers who are just sketching out rough designs.