Three-dimensional (3-D) printing is quickly becoming an important tool in the business world, but few can predict its impact on the supply chain sector.

Will demand for warehouse space shrink as manufacturers print the parts they need on demand instead of making them ahead of time and storing them in DCs? Will express parcel carriers see a drop in business as shippers e-mail digital designs instead of mailing physical parts? Or will 3-D printing be reserved mainly for filling niche demand for prototypes and replacement parts (the approach taken by a New Zealand airline that prints out replacement tray tables)?

Truck manufacturer Daimler recently helped clarify the situation when it announced it had begun using 3-D printing to produce spare parts. The announcement suggests that 3-D printing has matured beyond creating basic engineering prototypes and demonstration parts, and graduated to producing functional automotive-grade items.

Also known as "additive manufacturing," 3-D printing works by using a digital blueprint to direct specialized printers to create physical parts from substrates such as plastic, glass, metal, or ceramic. Daimler will use a version called selective laser sintering (SLS) that allows it to create high-quality plastic components, such as covers, spacers, spring caps, air and cable ducts, and clamps.

By allowing customers to order spare parts from digital catalogs, Daimler expects to save money by closing factory lines and eliminating stocking and warehousing costs for those seldom-needed items.