No matter what you design, you almost never achieve a flawless product right out of the gate. Rigorous testing, evaluation and refinement are the best means to assess what works and what doesn’t. Rapid prototyping with 3D printing provides the flexibility required to make this crucial trial and error process possible for physical products.
Reduce scrap and rework
In general, the later a problem is discovered, the more costly it will be to correct. Finding and fixing problems early in the design cycle is essential to preventing scrap, rework and retooling. Rapid prototyping with 3D printing allows industrial designers and engineers more revisions in less time, so they can test thoroughly while still reducing time to market.
Physical models convey ideas to collaborators, clients and marketers in ways computer models can’t. Rapid prototyping facilitates the clear, detailed feedback essential to product success, and lets designers quickly respond to input.
Test in the real world Know exactly how your products will look and perform before investing in tooling. A wide range of 3D printing materials can produce tough functional prototypes for highly accurate performance testing, or realistic models that look and feel like your finished products. Photopolymers, thermoplastics,
Plus, if your final production process will require molds, patterns or layups, you can 3D print short-run tooling to prove out your products and manufacturing processes before making big investments. source : http://www.stratasys.com/solutions/rapid-prototyping#sthash.rsTjhnxP.KfNMDEXH.dpuf