Financial accounting rules can be just as mutable as they are factual. What was once considered an asset on financial statements is quickly becoming a disposable expense for many manufacturing companies. As additive manufacturing, or 3D printing, becomes mainstream, thousands of manufacturing facilities are now fabricating jigs, fixtures, and manufacturing tools on a print-on-demand basis. Tools that historically have been expensive, labor intensive, and time consuming to produce, are now being designed and fabricated in days at a mere fraction of the cost. One company in particular, BMW, recognized this trend almost 28 years ago and is at the forefront of rethinking the way cars are assembled today.
Historically, auto assembly lines have utilized mill shops and 3rd party resources to fabricate tools that are used on-the-job by workers to assemble vehicles. These tools can range from standard wrenches fabricated to a specific bolt size, to complex vacuum-assisted robotic grippers . Previously, fabricating a single tool could take 7-10 days and cost $12,000; but with additive manufacturing the same tool can now be fabricated in-house, overnight for $2,000 . Fused Deposition Molding (FDM) and Selective Laser Sintering (SLS) are two of the most common technologies found in the manufacturing industry today. FDM utilizes heated thermoplastic material that is extruded into a printed design. This process is both simple and effective, but is limited to plastic derivatives. SLS uses lasers to sinter powdered material into the required design. This process has the benefit of being able to utilize everything from polymers to metal alloys. The main drawback is the expense and precision associated with operating this process, which requires 5kW of energy and temperature control within 1.8°F .
Today, additive manufacturing is being used to produce thousands of one-off and complex, small production parts. Before, when BMW wanted to test a new tool, they would perform a cost-analysis to determine if the material or time savings was great enough to justify the cost of the new tool. Furthermore, if the part was only used sparingly for unique installations or specialty requests, costs would be incurred to store the part for long periods of non-use . Today, BMW engineers develop a new design, fabricate it, field test it, and then iterate multiple prototypes until the perfect tool has been created. This revolution has allowed BMW to create specialty tools focused on everything from weight reduction to ergonomic advancements. One specific example is the 3D-printed “finger cots” which prevent workers from overstretching their thumb joint while pressing rubber stoppers into the vehicle frame . Another is an organically shaped bumper reach tool that reduced the time line workers take to install the rear bumper . Innovations like this that reduce worker injury and fatigue rates would have been too costly to test and produce only a few years ago.
The question that now remains is simple: where is the additive manufacturing industry headed and how will this affect the auto manufacturing industry? The immediate future is plagued by limitations associated with 3D printing. Most printers are designed for rapid prototyping rather than large-scale production. High material costs, inadequate quality control, and dependence on a small number of machine suppliers are the biggest limiting factors . Printing an object requiring less than 0.005 inch tolerance can drastically increase costs, and in an industry where part failures can cause injury or death, out-of-tolerance parts are immediately discarded . Nevertheless, manufacturing engineers continue to refine the additive manufacturing process, while advances in 3D printing technology continue to reduce overall costs. New and enhanced jigs, fixtures, and tools will continue to be developed and auto production lines will continue to be optimized and improved. BMW’s Munich facility already manufactures over 100,000 precision components and that number is only continuing to increase . The long-term future, however, is much more exciting. As technology advances and costs become economically viable, it is not unthinkable to imagine entire vehicles being constructed from additive manufactured parts. Even today, the BMW i8 Roadster’s top cover is only possible due to the weight reduction and strength increase that resulted from 3D printing the part .
In conclusion, we must not overestimate the growth and impact of additive manufacturing in the short-term, while alternately not underestimating the long-term impact and potential of this field. With an expected direct additive manufacturing market of $20 billion by 2020 and a forecasted total economic impact of $100 to $250 billion by 2025, it is clear that the auto production, and general manufacturing, landscape is on the precipice of change . As the industry moves forward and additive manufacturing rapidly expands into the mainstream, the questions will begin to shift from which technology is best, to what are the impacts on tangential industries. What will happen to the traditional supplier-consumer supply chain? What will become of manufacturing jobs replaced by technological advancements? Only time will tell.
 Joe Hiemenz, “3D Printing Jigs, Fixtures, and Other Manufacturing Tools,” Stratasys, Inc., 2011.
 Andrew Wheeler, “Coming Soon: A $5,000 SLS 3D Printer From Sinterit,” 3D Printing Industry, April 23, 2015, https://3dprintingindustry.com/news/coming-soon-a-5000-sls-3d-printer-from-sinterit-47428/, accessed November 2018.
 BMW, “Additive Manufacturing: 3D printing to perfection,” https://www.bmw.com/en/innovation/3d-print.html, accessed November 2018.
 Jorg Bromberger et al., “Additive manufacturing: A long-term game changer for manufacturers,” McKinsey&Company, September 2017.