Can you answer the question "What are the advantages and disadvantages of additive manufacturing specifically for Industry 4.0?" using the following information:

A small product size is perceived to be more suitable for improving time and
environmental performance, while a larger product size seems to have better
quality. Using metallic materials leads to a better performance in terms of time,
environment, and business flexibility, while plastic materials have a better cost
performance and ceramic materials have a better quality performance.
However, it is hard to generalize from these findings and comment on the future
of the technology since every day we see technological advances in equipment and
materials. In addition, every day we also see the successful application of AM in
new sectors. Therefore, most of these findings are only relevant to the current status
of AM technology.
6.3 Economic Analysis
In order to understand the size of cost-effective production volume, break-even
points can be considered as a useful measure. This measure is generally used to
determine when a business will be able to cover all its expenses and begin to make a
profit. In this case, the break-even points tell us the maximum size of production
volumes below which AM technologies represent a more cost-effective manufacturing process compared to conventional manufacturing. However, the break-even
point of production is case-specific, depending on technological aspects such as part
complexity, material and build volume.
In an early attempt to compare the cost per part of additive and conventional
processes, Hopkinson and Dickens (2003) studied SLS (additive) and injection
molding (conventional). The curve of injection molding (Fig. 6.12) clearly shows
cost-effective production at larger volumes because the initial costs (for instance of
the mold) are amortized across the production, whereas the cost per part for the
additive process remains constant from a single production to a larger production.
Fig. 6.12 Break-even analysis comparing laser sintering with injection molding. Source
Hopkinson and Dickens 2003
182 6 Strategic Alignment of Additive Manufacturing
However, they studied the RM application of additive processes, which is the
production of copies of the same product.
Ruffo et al. (2006) overcame the limitations of the previous study, by considering further components of the cost of production such as labor, materials,
machine, and administrative overheads. In contrast to the last study, the new
analysis has a curve with a saw-tooth shape to the filling of the machine bed space
(Fig. 6.13). It also shows the higher cost per part for single or lower production
volumes due to the initial costs of setting up. The break-even point moved from
14,000 parts in the previous study of 2003–9000 parts in the current study, thanks
to the newly developed cost estimation model.
Then, Ruffo and Hague (in 2007) looked at the capability of AM technologies in
the simultaneous production of different components, which may affect the cost per
part at lower production volumes. In other words, as seen in Fig. 6.14, the study
compared the production of copies of the same parts and parallel printing of mixed
components, both with an SLS system. The results demonstrate the efficient operational costs when simultaneously printing mixed components. The optimized mixing
of the components in the building platform also results in further cost savings.
The previously mentioned experiments considered objects that were additively
manufactured with plastic materials. So, for parts made of plastic, the results
demonstrate that the competitiveness of AM in comparison with conventional
manufacturing is well established. However, when considering the design optimization offered by AM, more cost effective operation can be expected as previous
studies did not consider the possible optimization, and the design file was that used
in conventional manufacturing. The potential design optimization comes from the
Fig. 6.13 Comparing cost models of laser sintering and injection molding. Source Ruffo et al.
2006
6.3 Economic Analysis 183
freedom of design to produce lightweight parts, complex structures, integrated
parts, hierarchical structures, and so on.
As discussed in Chap. 5, designers and engineers should consider the following
items if they are to achieve an optimum design with AM (Gibson et al. 2010):
• The possibility of using undercuts, flexible wall thickness and deeper channels
• The possibility of fabricating parts with unlimited complexity such as twisted
shapes, blind holes, and screw forms
• The possibility of combining several components into an integrated assembly.
With these aspects in mind, in an effort to evaluate the efficiency of AM production of metal parts, Atzeni and Salmi (2012) conducted an analysis involving the
comparison of the SLS of an additive process with high-pressure die-casting in a
conventional process, to look at possible design optimization. They employed an
EOSINT M270 machine (from EOS GmbH) and direct metal laser sintering (DMLS).
The sample part, an aeronautic component, (Fig. 6.15a) is the main landing gear of
the Italian P180 Avant II aircraft, built by Piaggio Aero Industries S.p.A. The
redesigned part (Fig. 6.15b) benefits from a reduction in the number of components
that need assembling and a reduction of as much as possible in material usage through
the use of undercuts and hollow structures, and a design for optimum functionality.
The cost components usually include materials, processing and tooling.
Processing costs consist of machine amortization, design and testing, labor, and
both pre- and post-processing. Tooling cost is only considered for traditional
manufacturing, for instance with high-pressure die-casting the cost of an object
consists of four main components—the cost of materials, the cost of the mold, the
cost of the process and post-processing per part. Likewise, the cost of an
SLS-printed part also contains four components: pre-processing, material, processing, and post-processing. The details of the cost per part in both high-pressure
die-casting and SLS processes are presented respectively in Tables 6.4 and 6.5.
Fig. 6.14 Comparing cost models of copies of single products and mixed components. Source
Ruffo and Hague 2007
184 6 Strategic Alignment of Additive Manufacturing
Furthermore, for the former, an assembly operation is required and the cost of the
assembly is calculated at the end, based on the production volume (N).
Based on the results obtained and the cost model, Fig. 6.16 illustrates the
break-even curves when comparing an SLS additive process with a conventional
high-pressure die-cast method for a part made of aluminum alloy. Specifically, SLS can
be considered as an efficient manufacturing method when the production volume is
lower than forty-two assembly components. However, the observed justifications were
more than just the economic aspects. For instance, the total process in the SLS method
took only 2.5 days, while pre-processing (such as mold production) took several weeks
in the conventional process, contributing in a reduction of time to market.
Table 6.6 shows the results of some other case studies that attempted to find the
maximum production volume at which AM can be cost-effective in comparison to
conventional processes. Five case studies are presented in the table. For instance, in
terms of metallic materials, Lindemann et al. (2012) compared selective laser
melting with a traditional subtractive milling process. AM can be considered as a
cost-effective manufacturing method for this part when the production volume is
lower than 190 in number. Broadly speaking, the maximum cost-effective production volume when using polymers for AM is higher than that for metal parts.
In these studies, the production time was measured experimentally in laboratories. Nevertheless, the ability to estimate the cost of production early is an
indispensable attribute and one of the main issues in the preliminary evaluation of
the technology. Several studies have proposed models for estimating the build time
and cost of products manufactured using AM technology based on artificial
Fig. 6.15 Main landing gear of the Italian aircraft P180 Avant II (a); and the redesigned part (b).
Source Atzeni and Salmi 2012
6.3 Economic Analysis 185
intelligence (Di Angelo and Di Stefano 2010, 2011; Munguía et al. 2009). Their
proposed parametric approach analyzes the geometrical features which typically
affect the build time of AM.
Obviously, the production cost of using AM technology is linked to the build
time, along with other drivers like materials. The build time depends on the characteristics of the additive systems, object geometries and complexity, and build
orientation. Build time is usually the summation of the time used for printing layers
and the delay between layers forming. Layer printing time is the time that the tool
takes to create the layer contours and the tool path loops. The tool path loops
depend on the tool path length and the number of tool repositionings. The delay
time between forming layers is employed for the solidification and cooling of the
deposited layers.
The build time of additive processes usually consists of seven main components
as follows (Di Angelo and Di Stefano 2011):
• Scanning time of the material contour
• Time for hatching material
Table 6.4 Costs for high-pressure die-cast parts
Components Unit Amount
Production volume (pcs) N
Material cost per kg (EUR/kg) 16.00
Part weight (kg) (kg) 0.162
Material cost per part (EUR) 2.59
Standard components’ cost (EUR) 1900
Mold cavities and slides cost (EUR) 15,400
Ancillary cost (EUR) 3700
Mold cost per part (EUR) 21,000/N
Machine cost per hour (EUR/h) 260.00
Cycle time (h) 0.001
Labor cost per hour processing (EUR/h) 35.00
Percentage of operator time (%) 10%
Processing cost per part (EUR) 0.26
Heat treatment cost per part (EUR) 1.42
Machining operations cost (EUR) 13.98
Labor cost per hour post-processing (EUR/h) 25.00
Operator time (h) 0.100
Post-processing cost per part (EUR) 17.90
Total cost per part (EUR) 20.75 + 21,000/N
Linkages parts’ costs (EUR) 0.50
Assembly cost (EUR) 0.04
Total cost per assembly (EUR) 21.29 + 21,000/N
Source Atzeni and Salmi 2012
Italics the cost per part
186 6 Strategic Alignment of Additive Manufacturing
• Scanning time of the supports’ contours
• Time for hatching supports
• Repositioning time of deposition tool
• Repositioning time of the supports’ deposition tool
• Delay time between deposition of subsequent layers.
Fig. 6.16 Break-even analysis comparing conventional HPDC process with SLS. Source Atzeni
and Salmi 2012
Table 6.5 Costs for part
made by SLS Components Unit Amount
Numbers of parts produced per job (−) 4
Material cost per kg (EUR/kg) 145.00
Part volume (mm3
) 0.060
Density of the sintered material (g/mm3
) 2.68
Mass of material per part (kg) 0.178
Material cost per part (EUR) 25.81
Machine operator cost per hour (EUR/h) 20.00
Set-up time per build (h) 1.2
Pre-processing cost per part (EUR) 8.00
Machine cost per hour (EUR/h) 35.00
Build time (h) 54
Machine cost per build (EUR) 1890.00
Processing cost per part (EUR) 472.50
Machine operator cost per hour (EUR/h) 20.00
Post-processing time per build (h) 13.98
Heat treatment cost per build (EUR) 20.00
Post-processing cost per part (EUR) 20.00
Total cost per assembly (EUR) 526.31
Source Atzeni and Salmi 2012
Italics the cost per part
6.3 Economic Analysis 187
Table 6.6 Break-even points of AM technologies compared to conventional manufacturing
Break-even point (in
pieces)
Printed
material
Process comparison Source
279–5800 Polymer SLA compared to injection
molding
Hopkinson et al.
(2006)
7500 Polymer FDM compared to injection
molding
Hopkinson et al.
(2006)
14,000 Polymer SLS compared to injection
molding
Hopkinson et al.
(2006)
42 Aluminum SLS compared to high-pressure
die-casting
Atzeni and Salmi
(2012)
190 Steel SLM compared to milling Lindemann et al.
(2012)
Table 6.7 Sub-processes involved in typical commercial AM technologies
Systems Sub-Process
Material Support
Border scanning Area scanning Border scanning Area scanning
SLA YES YES YES YES
SLS YES YES NO NO
SLM YES YES NO NO
FDM YES YES YES YES
LOM YES NO NO YES
3DP NO YES NO YES
EBM YES YES NO NO
Adapted from Di Angelo and Di Stefano 2011
However, as discussed in Chap. 1 the processes of AM technologies are different, resulting in different processing time components. For instance, as seen in
Table 6.7 the sub-process involved in typical commercial AM technologies, which
are the driving factors of processing time.
In parametric build time estimation, driving factors play an important role in the
process. These factors can be identified through the STL standard definition of the
geometric model. Eight parameters (Vmat=Lmat,
bzmat=Lmat ,pmat; nrmat , Vsup=Lsup,
bzsup=Lsup, psup, nrsup) consider the dimensional features of the object and the
dimensional technological parameters.
where:
Vmat Volume of material to be printed; Vsup (for support)
Lmat Layer thickness; Lsup (for support)
bz−mat Object’s height; bz−sup (for support)
pmat Total length of the layers’ contour to be deposited; psup (for support)
nr−mat The number of repositioning movements; nr−sup (for support).
188 6 Strategic Alignment of Additive Manufacturing
Using the above-mentioned estimation model, companies can estimate the build
time and can then estimate the production cost of a part with AM. Therefore, they can
see whether or not the AM technologies are cost-effective when compared with the
existing manufacturing methods in the initial stages of implementing the technology.
Exhibit 14—Economical Analysis—Return On Investment
Return on investment (ROI) takes into account the gain or loss generated on
an investment relative to the amount of money invested. It allows one to
compare the efficiency of different investments. Therefore, one parameter for
comparing AM with conventional manufacturing is to know the profitability
of any investment. Studies and practitioners confirm the benefits of AM
technology in terms of production and business opportunities, because since
AM enables toolless production and needs a smaller production line, it can
reduce operational costs. AM may offer a much better investment opportunity
in comparison with conventional manufacturing, particularly for high-value
parts with low-volume production.
More than 43% of the respondents believe that AM is not good for profitability of investment. This may be due to the higher initial investment in
equipment in some circumstances such as the production of parts made of
metal or those with a need for greater precision. AM machineries have to
fully consider this performance indicator so as to reduce the amount of
investment required by as much as possible. Notably, AM adopters can also
think of creating new business with those assets and/or should consider how
to take full advantage of the technology’s potential.
6.3 Economic Analysis 189
Seven Key Facts
• AM can drive competitiveness for developed countries because it needs
fewer resources.
• AM is more advantageous for small and medium enterprises because of
their flexibility.
• AM is an efficient manufacturing method for small to medium production
volumes.
• AM is an effective manufacturing method for parts with complex shapes,
customization requirements, and creative designs.
• The operational performance using AM for prototyping is more efficient
than manufacturing end-usable products.
• The operational performance when using AM for small-size products is
more efficient than large ones.
• Approximately 57% of AM adopters believe that AM is better than
conventional manufacturing in terms of profitability of investment.

AM technologies are beginning to move beyond a common set of basic process
steps. In the future we will likely see more processes using variations of the
conventional AM approach, and combinations of AM with conventional
manufacturing operations. Some technologies are being developed to process
regions rather than layers of a part. As a result, more intelligent and complex
software systems will be required to effectively deal with segmentation.
We can expect processes to become more complex within a single machine. We
already see numerous additive processes combined with subtractive elements. As
technology develops further, we may see commercialization of hybrid technologies
that include additive, subtractive, and even robotic handling phases in a complex
coordinated and controlled fashion. This will require much more attention to
software descriptions, but may also lead to highly optimized parts with multiple
functionality and vastly improved quality with very little manual intervention
during the actual build process.
Another trend we are likely to see is the development of customized AM
systems. Presently, AM machines are designed to produce as wide a variety of
possible part geometries with as wide a range of materials as possible. Reduction of
these variables may result in machines that are designed only to build a subset of
parts or materials very efficiently or inexpensively. This has already started with the
proliferation of “personal” versus “industrial” material extrusion systems. In addition, many machines are being targeted for the dental or hearing aid markets, and
system manufacturers have redesigned their basic machine architectures and/or
software tools to enable rapid setup, building, and post-processing of patient specific small parts.
Software is increasingly being optimized specifically for AM processing. Special software has been designed to increase the efficiency of hearing aid design and
manufacture. There is also special software designed to convert the designs of
World of Warcraft models into “FigurePrints” (see Fig. 3.3) as well as specially
designed post-processing techniques [3]. As Direct Digital Manufacturing becomes
more common, we will see the need to develop standardized software processes
based around AM, so that we can better control, track, regulate, and predict the
manufacturing process.