When you ask an industrial designer what is the most important thing to take into consideration when designing for manufacturability, you will like get the following response, "It all comes down to the intent of the product and what will make it successful and meaningful." Many designers will agree if a product is designed to provide a rich experience for the user, then all efforts must be directed into that area -- even at the expense of challenging the most straight forward manufacturing processes. The iPhone is just one example of a product that could have been created with less effort to save every phase in the manufacturing process a great deal of time and money; however that, might have been detrimental to the final consumer experience. The iPhone's popularity and sales undoubtedly justify any iterative design process and approval to manufacture a complex product design. "Rapid manufacturing and additive technologies are exciting and new, but should only be used if the final product experience requires and justifies it," says Scott Summit of Summit ID. "That being said, there are many areas where the unique benefits of rapid manufacturing can solve a human need in ways that traditional manufacturing cannot." For example, the ability to quickly evaluate a prototype for fit and function; as well as, the ability to quickly manufacture a product with additive processes like Selective Laser Sintering and 3D Printing.

Economics and Scheduling 
While most manufacturers believe that product design and customer service may be the ultimate way to distinguish a company's capabilities in a competitive marketplace, some believe a designer's primary objective is to design a functioning product within given economic and schedule constraints. Even still, Designing for Manufacturability can impact a company's success and profitability as research has indicated that the decisions made in the first 5% of product design can determine the majority of a products cost, quality and manufacturability characteristics. "The application of Designing for Manufacturability must consider the overall design economics." Kenneth Crow of DRM Associates. "It must balance the effort and cost associated with development and refinement of the design to the cost and quality leverage that can be achieved." Research has also shown that decisions made during concept development can commit 60-70% of a products cost and decisions made through detailed design of the product and process can commit 80-90% of a products cost. Still most manufacturers agree, efforts to optimize a product's design can be justified with high-value or high-volume products, for example, medical devices and high-end consumer products. This is indicated in the following figure:

 

Part Shapes, Costs and Product Volume
"When designing a product that will be manufactured through processes such as cast urethane or injection molding, it is important to take into consideration the part shapes, costs and product volume," says Dale Dell'Ario of Ario Design. Generally one associates injection molding and die casting with high product volumes. These processes result in relatively inexpensive parts and require significant investments in tooling. Additionally they place constraints on designers. Some examples; the least expensive tooling requires that parts have tapered sides known as draft. Undercuts in the sides of parts must generally be eliminated be able to get parts out of their tools. Parts may be made with no draft and undercuts accomodated with more complicated and sometimes dramatically more expensive tooling. More design time may be required as well. The industrial designer therefore must juggle desired functionality and form with tooling budget. Rapid manufacturing additive processes, urethane parts made from flexible tooling, and traditional casting processes sidestep the constraints of draft and undercuts, and all result in higher part costs, hence the maxim, low volume comes with high part cost and high volume (low cost) parts come with big tooling outlays.