Here's a great white paper written by RapidMade Co-Founder and Advisor Mark Eaton:

Investing in 3-D printing technology can provide significant business advantages. Product development, customer value, manufacturing costs and product life cycle management can all be positively impacted by this technology. Determining where to make the investment requires careful consideration of the expected outcomes and thorough analysis of the business, processes or products that will be impacted by the investment.

For companies considering investing in 3-D printing, outsourcing to a reputable service bureau is a viable, cost-effective alternative that is less susceptible to changes in technology and materials than in-house ownership. The benefits derive from eliminating the initial capital cost of the equipment and the infrastructure setup cost to avoiding the operating costs of ownership and obsolescence issues relating to the rapid development of 3-D technology.

History of the 3-D Printing Market

The technology for 3-D printing, also known as additive manufacturing, has existed since the 1980s. Although the additive manufacturing market took approximately 20 years to reach $1 billion, five years later in 2012, it had reached $2 billion. By 2013, consensus estimates by Gartner and Wohlers indicate it had reached $2.5 billion. A significant portion of this revenue was derived from 3-D printer sales, but estimates by PwC and ZPryme indicate that by February 2014, 67 percent of manufacturers who responded were already testing or using 3-D printing.

Despite advances in speed, reliability and material availability, 3-D printing has to this point still been largely used for prototyping, testing and tooling. Although rapid prototyping remains important, the pivot to printing more fully functional finished products and components is the direction that analysts see the sector heading.

For example, GE plans to mass produce 25,000 LEAP engine nozzles using additive manufacturing and already has $22 billion in commitments, said Dr. Mark Cotteleer of Deloitte Services in October 2014. Medical, dental and automotive are other sectors that report increasing use of 3-D printing to create fully functional parts.

Yet, in a recent December 2014 Gartner worldwide study, 60 percent of respondents cited the high acquisition and startup costs as delaying their investment in 3-D printers. Of those surveyed, 37 percent had just one 3-D printer within their organizations, with 18 percent owning 10 or more.

The average number of printers per organization was 5.4. One interesting finding was that respondents felt overwhelmingly that using a 3-D printer as part of their supply chain generally reduces the cost of existing processes, especially research and product development costs. The study concluded that those companies who were using the technology for product development were seeing a 4 percent improvement in costs.

Types of Technology and Materials

Despite the widely held mistaken belief that 3-D printers can "print anything," commercial manufacturers and product developers are still faced with the reality that there are many types of 3-D printing processes. Each process has speed, part tolerance and quality-related factors to consider.

Similarly, each 3-D printer is designed to work with a select set of materials. Most commercially available 3-D printers (often called professional or production printers) are designed to work with either plastic or metal. However in the case of plastic, the material or polymer will vary depending on the 3-D printing process, as will the mechanical, aesthetic and functional properties of the finished part.

UV-cured polymers behave differently to laser-sintered nylons. In the case of metals, parts printed on a laser-sintered machine will have different properties to those produced on an electron-beam or laser-melt style printer. Complexity further increases when the user has to consider ceramic, biomaterials and/or materials needing regulatory approval, which may require not only specialized materials, but printers with unique attributes.

Most materials, often termed feedstock, are pre-processed to create the liquid or powder that is ultimately reformed as a printed part. The cost of materials is a significant factor in the adoption of 3-D printing. Depending on the material type, prices can range from $35 to $600 per kilogram; specialty materials that have unique applications can be much higher.

In many cases, companies that supply 3-D printers try to control the material supply using, for example, prefilled cartridges or other means. Of late, this practice is beginging to change as new 3-D printer manufacturers enter the market, alternate material suppliers emerge and machine owners determine how to override printer settings. In fact, the study conducted by Roland Berger showed that experienced 3-D printer owners had effectively created their own supply chain, and this was driving down material costs.

Traditional Manufacturing Comparisons

Three-dimensional printing is still in the early adoption phase when it comes to the production of finished components and products. Speed of printing has yet to match the rates of typical mass production techniques. Companies such as GE, Siemens and Autodesk envisage 3-D printing being used in conjunction with or alongside traditional manufacturing techniques.

The rate at which 3-D printing will supplant traditional manufacturing techniques, such as CNC machining, injection molding or casting, is openly debated and will largely depend on advances in technology, materials and software.

But according to a recent Siemens report by Sandra Zistl, "Even though analysts at WohlersAssociates expect the rapid prototyping market to grow to more than $5 billion by 2020, 'Money will be made with manufacturing, not with prototypes,' forecasts Tim Caffrey, a consultant at Wohlers." This assessment is shared by Bernhard Langefeld, a machine construction expert at Roland Berger Strategy Consultants and one of the authors of the study titled "Additive Manufacturing – A Game Changer for the Industry?"

What is also often a source of debate is the degree to which commercial manufacturers and product developers should own or outsource 3-D printing technology. Here we have to turn to traditional methods for evaluating capital investment and make-buy decisions. At the same time, we have to consider the risks of obsolescene, premature adoption of new technology, and the true cost of ownership.

In order to asses the capital investment or make-buy decision, we first must understand the expected financial and commercial returns from the decision, and to do that, we have to carefully consider the benefits of 3-D printing technology and where to apply it.

The capital cost of acquiring a professional or production 3-D printer varies tremendously. UV polymer printers vary from the mid-$30,000 range to $200,000 for the more complex machines. Metal-laser sintering machines will cost anywhere from $500,000 to $1 million-plus. It is also important to realize that just like traditional manufacturing, there will be additional costs for cleaning systems, dust collection, chamber gas-delivery and recovery systems, and for more sophisticated printers, complex material handling systems will be needed. Similarly, space and building requirements have to be considered, as do machine layout, material flow and cell design.

Three-dimensional printing is able to create a part directly from a digital file. However, this creates additional considerations because the ability to create an effective part is a function of the quality of the file; for example, is it an accurate representation of the desired finished part? Software that can manipulate the file to change the structure of the part or that can adapt the file to more effectively print the product is also available.

For each printer type, there is often a need for different types of software. The costs of this software must also be conisdered as part of the capital investment. Workflow software is also required when managing multiple files and parts if the production of these parts is to be efficient.

3-D Printing Applications

As this white paper indicates, there are many potential applications and markets for 3-D printing technology. In general, these can be 

characterized into four primary categories; marketing and promotion, product development and design; production elements such as tooling, fixtures, products and components; and business services.

When considering an investment in 3-D printing, determining the application or intended purpose requires the investors to make a careful assessment of their existing business, process or product. Secondly, it requires a clear understanding of the expected outcomes from the investment; reduction in product development time, increased customization, lower supply chain costs, improved quality, new commercial opportunities and added customer value are some of the examples often cited for investment.

For example, the United States Postal Service estimates turning postal processing centers into 3-D printing hubs could generate $646 million in commercial packaging revenue. However, reaching such a conclusion requires analysis and investigation of multiple factors as well as a thorough understanding of available technology, materials and software. In these cases, businesses are turning to existing 3-D printing companies such as Stratasys, RapidMade and Baker 3D Solutions to help them navigate the decision process.

3-D Printing Total Cost of Ownership

Having identified the need for investment in 3-D printing, the business leader is most often faced with the make-buy decision (or in-house vs. outsource). A number of factors must be considered.

Traditional factors such as the protection of intellectual property and the critical nature of the product or component remain important. Of additional importance is the degree to which the 3-D printing technology itself is evolving. In 2009, the FDM patents expired, which led to the launch of many low-cost desktop copies. Similarly, in 2014, the SLS sintering patents expired, and this is expected to impact the cost of these printer types. Three-dimensional printer speeds are expected to increase fourfold over the next five years with companies such as Siemens stating that material feed rates will improve from 10 cm3/hr to 80 cm3/hr.

While many 3-D printing manufacturers market and advertise the simplicity of these machines, the reality is that print builds fail and need to be reprinted. Similar to traditional manufacturing processes, there are usually post-processes required to finish the product. There are waste streams that have to be managed; support material often has to be removed, and production has to be planned to ensure the printers run efficiently. Labor operating costs are similar to modern CNC machines, although these can be automated if volumes dictate.

For a typical commercial manufacturer or product developer who is producing products constructed of multiple materials and components, multiple 3-D printer types will be required. It is not uncommon to require multiples of the same machine because print rates sometimes result in daylong builds. The Gartner survey from December 2014 found that, for those owning 3-D printers, the average number of machines owned was 5.4. For a simple product development, for example, it is not uncommon to need three different types of 3-D printers.

This total cost of ownership analysis and the recommendation to buy versus make is very similar to the analysis that would been done for a traditional machine tool. What is the labor cost to operate; what are the waste factors; what are the utilization rates; what are the utility and space considerations; what are the maintenance costs, etc. Factors that will also need to be considered are the material limitations of each 3-D printer type, the software and the pre-processing that is required along with the associated costs.

In most cases, there will be fixed engineering and operating support costs that will have to be applied over the planned usage hours. Consumable costs will include materials as well as print heads, UV lamps, lasers, build plates, support material, part-cleaning solutions, chamber gas, etc.

For many situations, the option to buy from a "service bureau" will be more cost-effective than owning the technology. As with traditional manufacturing, a service bureau can specialize by using one type of 3-D printer or by better leveraging costs over aggregated production volumes.

As a cautionary note, it is important to select a reputable service bureau. Not all 3-D printers are built to the same quality and their ability to maintain build tolerance or part strength will vary. So it is important to understand how the part will be printed.

As with traditional manufacturing, service bureaus can be differentiated by those that have engineering expertise, a quality management system, a maintenance program and certified technicians compared to those that do not. Just like traditional manufacturing, there are print tolerance limitations that have to be considered in the design, and a service bureau with embedded engineering capabilities will be able to address these issues.

Consider also the importance of ensuring that the material supply chain is robust. Whether the decision is made to print In-house or through a service bureau, control of the material supply chain, both from a traceability and a material compliance viewpoint, is a consideration.

For mission critical or complex materials, organizations such as the Lawrence Livermore National Laboratory can provide independent certification of the material. In general, because these are essentially created materials, their properties will approximate but not always replicate traditional materials. Having access to knowledgeable resources will help avoid common pitfalls.