Manufacturing
CAD is a powerful tool in product development, but leveraging manufacturing knowledge is even more crucial to ensure designs are valid and avoid wasting time and resources.
For a design to be feasible to produce, it's critical to focus on its purpose, compatible materials and manufacturing process(es), interfaces with other parts, and expected/allowable tolerances. Awareness of these factors during design minimizes the number of design iterations (and therefore time and costs) needed to produce a satisfactory final design.