Benefits and costs of additive manufacturing applications: an holistic evaluation guideline a
M. Zanardini1, A. Bacchetti, M. Ashour Pour, S. Zanoni a Department of Mechanical and Industrial Engineering, University of Brescia, Via Branze, 38 – 25123 – Brescia, Italy
Abstract. With an ever growing diffusion of additive manufacturing (AM) system in industrial and consumer level, as well as the direct and indirect dynamics which are being introduced resulting from its inclusion as a viable production system on companies’ portfolio, the need to reconfigure production system and adapt the production line becomes even more relevant than before. There are several studies which have emphasized on the importance of a paradigm shift in order to exploit advantages of AM, not only considering design and functionality of the product but also with regards to its impact on the entire value chain reconfiguration. Thus, it is of crucial importance to take into consideration that for this shift to be feasible and manageable, it needs to include both technical and managerial aspects of manufacturing. This work proposes a new perspective to provide a guideline for the proper evaluation of AM implementation from a holistic viewpoint. Starting from a priori analysis, the authors provide a three-steps evaluation guideline, thanks to which companies interested in AM could verify both technical and economical feasibility of its implementation, comparing it to the conventional subtractive techniques. At the end, the proposed guideline is tested in two real case studies. Keywords. Additive Manufacturing, Evaluation guideline, Case study
1. Introduction Considering their evolution rate, Additive Manufacturing (AM) technologies are becoming more interesting for a huge spectrum of industries and the applications will soon impact also the production activities of components and products [1]. AM is subjected to a dual trend: from a non-scientific point of view, it manifests an overflow of available data; from a scientific standpoint, the literature is often not sufficient for the practical evaluation of these techniques, lacking specific guidelines that can help non-experts attain the necessary know-how. The authors have found that the scarce available literature is not completely aligned with companies’ requirements which are focusing mostly on technological aspects and without providing an holistic view that ensure the evaluation of all the benefits and limitations of AM. In order to highlight the main limitations, four categories have been identified:
1
Department of Mechanical and Industrial Engineering, University of Brescia, Via Branze, 38 – 25123 – Brescia, Italy; E-mail:
[email protected]
i.
The data provided are often not up to date (and generally refer to a particular technology or even to a particular machine); ii. The majority of the works consider a specific technology, and do not provide a priori analysis for identifying which is the most suitable for the context of application; iii. As a consequence of point ii, the economic analysis generally does not compare different technologies to evaluate which is the best one. Considering that each technology encompasses several machines (by different manufacturers), this would lead to a significant limitation of the proposed analysis; iv. According to the point iii, the models compare production costs, but do not consider the investment decision analysis. In order to overcome the shortcomings described above, this work provides a holistic guideline for evaluating proper use of AM technologies. The main objectives can be summarized as following:
To define a guideline to support manufacturing companies to understand whether AM techniques are suitable for their context and products, proposing criteria valuable for an a priori analysis, and providing a list of the (eventual) appropriate technologies and related machines;
To provide a model for the evaluation of the economical convenience of AM application, compared to the conventional subtractive technique.
2. AM paradigm In order to have a better understanding of AM, it is necessary to look at it from the system point of view. This is due to the wide range of impacts that is accompanied by its implementation: extending from raw material suppliers and procurement, towards production level, distributors and even customers. A systematic analysis allows for characterization of the system to address all of its attributes. AM, just like any other kind of manufacturing system has its own cons and pros and thus, a rigorous investigation of its mechanism is required. AM is a term applied to a technological class which consists of multiple subsets that make up the technological variations. Each of these technologies could be applied in various industries ranging from consumer goods to medical and aerospace. 2.1. AM Characterization One of the most remarkable aspects of AM which has enhanced its position among other manufacturing techniques is the flexibility which not only enables economical low volume production [2] by eliminating the need for tooling, but also provides product designers with a degree of freedom that no more limits functionality in favor of feasibility of the process. This feature provides manufacturers with two remarkable opportunities regarding the design: faster time-to-market, and almost real-time design changes that happen as improvements and optimizations are made to the original design. According to [3], special features of AM would result in the following benefits. No tooling is required
Economic production of small batches becomes feasible High flexibility for changing the design of the parts/products Optimization for product functionality would be achievable Products and design customization which are based on individual customers’ needs High possibilities of wastes elimination during production phase Possibility of having simpler and shorter supply chains Another study [4] characterizes AM by highlighting its distinguishing features. High automation and part consolidation which provides the possibility to build parts as a single piece and therefore eliminate the assembly would consequently lead to a great reduction of the labor, storage, handling and logistics costs. Economies of scale are one of the most remarkable properties of mass manufacturing. Manufacturing in large volumes allows for reduction of cost per unit as a result of the fixed-cost proration. However, since AM machinery requires no setups, production in small batches becomes economically feasible and this is a direct result of economies of one. Economic inefficiency in large volume production, inability of processing large parts due to the chamber size limitations [5], process variability [4] and lack of consistency among produced parts to ensure mechanical properties of the parts [6], incompetency of the companies who are struggling with process automation and digitalization, limited range of raw materials and lack of international standardization are amongst the most important barriers towards considering AM as manufacturing method. 2.2. AM technology variations Different approaches have been introduced to classify AM processes. One classification is based on the raw materials feed. Accordingly, the processes can be divided into the classes which use four types of input raw materials[6]: polymers, metals, ceramics and composites. Another type of categorization is based on the working principle of process: liquid, filament/paste, powder, and solid sheet [6]. Yet another type of classification is based on the “method to fuse matter on a molecular level” and consists of: thermal, UV light, laser or electron beam. Finally, there is another classification of process technology which is introduced by ASTM F42 committee. The notable areas in which AM has been deployed with high rates of success are currently limited to medical devices, consumer goods (e.g. electronics), aerospace, automotive, jewelry, architecture and defense [2]. Although various studies have considered the issue of energy usage in AM machines, a unified and standard procedure to measure energy consumption is still lacking and there needs to be more data for making comparisons among conventional technologies and AM. However, there are multiple studies [7] which show when it comes to the environmental aspects and carbon footprint, AM has a positive impact. Needless to say that a majority of these researches would still pinpoint the focus of their investigations into the lack of detailed information regarding wastes, energy consumption and environmental impacts.
3. Impactful dynamics of AM As it was mentioned earlier, AM is a system which is attributed by a variety of dynamics. One of these attributes which directly impacts the value chain is the supply chain management. The ability to redesign products with fewer components and the possibility of manufacturing products near the customers’ physical location are two opportunities offered by AM [5]. This would not only reduce the need for warehousing, transportation and inventory turnover, but it would also make the supply chain simpler by reducing the time-to-market and lead-time. Design for Additive Manufacturing (DFAM) is a term which is used to emphasize on the flexible aspect of AM; meaning that since there are no limitations imposed by the design of the product to reduce its functionality, parts can be redesigned into single components and thus, AM’s capabilities would be exploited in a more efficient way. By doing so, a reduction of the materials, energy and natural resources would take place which would eventually result in significant sustainable and economic benefits. An exciting area for AM to implement is in the spare parts supply chain. A thorough investigation [8] of spare parts supply in aircraft industry shows that rapid manufacturing (which is a term used for AM of individual parts/small lot sizes) can be used for low volume production of parts in a centralized location and at the place of consumption, if inventory holding and logistics costs are high in comparison with the production costs. This strategy would keep stock level down and AM capacity utilization high. In another study [9] four scenarios were studied in two dimensions of supply chain configuration (centralized and decentralized) and AM machine technology (current and future technology). One significant outcome of the study showed that with the current maturity of AM in which machines are both capital- and labour intensive, centralized production is more efficient, while with the evolution of technology in the future, characterized by cheaper and more automated machines, distribution of production would be a better choice for the spare parts supply chain. Although lack of enough supporting data to measure sustainability aspects of AM is a big impediment to research, some researchers have tried to identify the key concepts of AM which are relevant to sustainable manufacturing [7]. These are the same advantages that distinguish AM from conventional and traditional manufacturing processes. Considering the current legislation and regulatory laws that exist on the environmental aspects of manufacturing processes, and manufacturers’ tendency towards moving to cleaner and more sustainable production, the environmental impacts of AM is part and parcel of any analytic assessment. An analytic model on the evaluation of environmental impacts in AM [10] which considered the whole environmental flows, shows that in order to study the global environmental impacts, not only the electricity power consumption, but also the materials, and fluid consumption need to be taken into account.
4. State-of-the-art of AM adoption frameworks An extensive evaluation of the existing literature has been provided in order to evaluate correctly the new possibilities enabled by AM technologies. The high diffusion pace of the technology in the last years [1] is immediately evident also in the yet limited literature available: excluding the technical papers, that treat the technology from a mechanical and physical point of view, the contributions that consider AM
technologies from a managerial stand point are scarce. Indeed, fewer are the papers that define models and frameworks useful for evaluating the cost and benefits associated to these techniques, in comparison with traditional ones. A complete and rigorous database is developed. 72 articles have been fully classified. 15% of the articles is dated before 2007, 52% are from 2012 onward. The majority of them are scientific (80%), but also the researches of consulting company can have a significant role, considering their specialization to elaborate forecast about future development of these new technologies. Below, are presented the most relevant papers that propose economical models thanks to which a company could evaluate if 3D printing is convenient for its activities and products, making a short literature review usable for identifying the main gaps versus practitioners requirements. Generally speaking, AM is considered convenient for small series of complex pieces and rapid prototyping activities [21], but in the last years 3D Printing has become mature not only for prototyping but also for industrial production [22]. With the increased relevance of 3D printing, nowadays researchers are putting more efforts in the identification of a costing model that compute the production costs of each AM techniques. Till now, the literature does not yet provide a set of models and algorithms valuable for evaluating the real convenience compared to conventional techniques (e.g. Injection molding, CNC machining). One of the first contribution in this research stream comes from [23], that proposed a first model for the estimation (and the comparison) of the production cost by FDM and SLA. The model considered the printing and pre and post-processing activities costs, identifying that the production costs was very influenced by the chosen orientation of the pieces in the printer chamber. However, this model had some weaknesses for serial production (among which the limited processes and technology treated), making it valuable only for prototyping activities. 5 years later, [11] provided a more appropriate model for production activities, that analyzed the direct cost of production considering the machine costs, labor costs and material costs (omitting the overhead costs and the energy consumption). The proposed model evaluates different additive manufacturing techniques (Stereolithography (SLA), Laser Sintering (LS) and Fused Deposition Modelling (FDM)), for the printing of a single piece continuously for a year. One of the most relevant output of the work has been the evaluation of the typical 3d printing cost profile, not dependent on the quantity produced (in some following studies this result is discussed more deeply and confuted especially for small production batches). [12] provided some improvement from the economics evaluation point of view to [11] model, due to the exploitation of activity-based costing (ABC) methodology for evaluating the 3D Printer product full cost. This model shows that the production costs for low volume depends on the number of pieces produced (this not linear pattern is caused by different sources of inefficiencies during the production process, related to powder waste and printer saturation). The proposed model had strong limitation considering only one single technique as Laser Sintering (LS). [12] confirmed the previous assumption that the more production chamber is saturated the more the unit cost production is reduced. The models provided in the following years, by [24], [22] and [25], tried to evaluate the cost of 3D printing application in a holistic view, considering a Life Cycle Approach (LCA). In these works, the authors encompassed (with different range of adoption) also the re-design activities, required for a fully exploitation of 3d printing capabilities and incorporate the fully advantages enabled by additive manufacturing
during the use of the products by customers. For example, the reduction of weight enabled by AM (especially in the aerospace industry) can have a substantial impact on product life cycle costs, generating relevant savings due to the reduced product’s weight. [26] and [27] underlined how the capacity utilization rate of the printer is a relevant parameter for the economic evaluations of the different additive manufacturing techniques, proving also an algorithm to optimize the products configuration within the build chamber. The costs for laser sintering application may differ up to 30% with different configuration (but considering the same products). [28] presented a new cost model for SLM, based on [11] and [12] models, that take into account adequately all pre- and post-processing operations. These activities are relevant especially if high-quality standards for functional parts have to be achieved. In the last years the focus has been shifted from a simple operational point of view, to a more strategic perspective. The main aim of this last stream of research is to propose some metrics that can be exploited for an a priori evaluation of which companies businesses and products best fit an additive manufacturing production. To cite one, [15] proposed a methodological framework which combined Multi-Criteria Decision Aid (MCDA) and Data Envelopment Analysis (DEA) for the determination of the optimal production strategy according to firm and market characteristics. Also [16] provided a framework for determining if AM is an appropriate fit for different businesses, evaluating three key attributes: production volume, customization, and complexity of the selected products (range of products). The approach considered by [17] is one of the most comprehensive: first, they identified a list of possible products that may be revisited by additive manufacturing production (selected considering the well-established factors as complexity and volume), then they evaluated for each the most appropriate 3D printing technique that match the firm’s requirements, and only at the end of this evaluation process the authors developed an economic analysis. Considering a more consultancy-oriented approach, one has to notice Senvol (included in 1), the company which experts in AM machinery and applications based in the US. In the paragraph titled “Cost-Benefit Analyses for Final Production Parts”, the authors explain the applications of their cost evaluation model. Contrary to the previous works cited earlier (e.g. [11]&[12]), and due to the inefficiencies caused by print batches, their model does not provide a constant production cost. Thus, until the printing chamber is not completely saturated, the production cost per part provided is not constant. Considering the assumption that the more the machine is saturated, the lower is the final production cost per part, previous scientific works that hypothesize to fully load the printer capacity seem more attractive. This assumption is reasonable, taking into account that (due to the absence of setup costs) a given company could saturate the build chamber with other parts/products and hence produce with a fully saturated chamber
5. The proposed evaluation guideline According to [15], nowadays companies need more support in order to evaluate whether or not AM could be suitable for their activities and products, and academics have to propose guidelines that help “senior management to reconsider whether they will continue using current production technologies, or they could benefit by exploiting
the benefits of modern AM technologies”. In accordance with this statement, and the results of the above presented scientific literature review, the authors have identified a logical path that a company approaching AM for the first time could follow for a comprehensive evaluation of the AM techniques (Figure 1).
Figure 1. Proposed AM evaluation framework.
Considering the main lacks described in the introduction, the guideline aims to provide a complete assessment of this new paradigm, considering not only an economic evaluation or a context/product analysis but also a comprehensive assessment of the alternative AM technologies that can be employed. The text provides an a priori analysis of the AM applications, considering the main features of the company context and products properties, and then proposes a technical and economic model to provide data for a quantitative assessment. 5.1. Preliminary assessment The first step that a company should perform to understand whether these technologies may bring advantages to its business is a preliminary (qualitative) assessment of the context in which operates.[16] provided a framework that encompasses three key attributes: production volume, customization, and complexity of the products. Simkin and Wang of Senvol [1] proposed 7 different scenarios that “lend themselves well to AM”. These scenarios consider elements that range from manufacturing cost, required lead time, inventory cost, supplies risk, logistics cost and finally to the need to develop products with improved functionalities. When a product falls into (at least) one of these categories, a more precise assessment is warranted. Also [16] provided a framework that encompasses three key attributes: production volume, customization, and complexity of the products. The works cited do not provide quantitative drivers for an easy evaluation of which products are more promising for AM. Indeed, it is argued that already in this preliminary step a company should consider indicators related both to product and supply chain features for identifying which products (or range of products) could be encompassed in the following evaluation steps. For this reason, four different quantitative drivers are introduced that permit a selection of the most promising products for AM: Cost weight intensity = (Product overall cost [€])/(Product weight [kg])(1) Buy to fly = (Total material consumption [kg])/(Product weight [kg])(2) Mould cost intensity = (Cost of the mould allocated to the product [€])/(Product overall cost [€])(3)
CNC time intensity = (CNC time consumption [h])/(Product volume [dm^3])(4)
5.2. Technical assessment The next evaluation phase takes the input from selected products of the last stage, aiming at evaluation of the technological feasibility to manufacture them through AM. A more quantitative analysis is performed in order to map some relevant product features that have to be considered in this technological assessment: dimensions, materials, physical and mechanical properties, and so forth. The comparison of these parameters with a machines’ database ensures to identify the (eventual) technologies and the related machines that are suitable for the company’s products and needs. The output of this step is a list of (technology and) machines that fulfil the company’s requirements, along with information about the machines price and the resellers that could provide it. 5.3. Economical assessment By identifying the list of feasible machines, it is possible to perform a preliminary evaluation of the cost occurred by the company. The provided tool aims to overcome the general lack of the existing model described in literature: i. The model takes in account all the data collected in the technical database, considering the 108 printers categorized. The real value of the previous database consists in the amount of data collected that enables the economic cost evaluation for (at most) all of the different technologies and printers. ii. The model considers the investment required to purchase a specific printers and encompasses this cost element in the analysis performed. The developed model ensures to perform two different types of analysis: one for evaluating if products or components made by AM are more cost-effective than the same products or components realized through conventional subtractive techniques (injection molding or CNC machining), and the other one for evaluating which of the different AM technologies (or printers) that fulfill company’s needs is more costeffective, overcoming a general limitation of the literature. According to [11], the provided model computes the direct cost of the AM application in terms of machine, materials and workforce. Indeed, thanks to the rigorous data collection, the cost related to the maintenance activities that [12] took into account as indirect cost, is considered to be a direct cost.
6. Case studies 6.1. Automotive case: evaluating different 3D printing technologies The proposed case study considers a company that has exploited AM since 2001, and reached a high level of knowledge especially on SLA. The company belongs to the automotive sector (specialized in the production of racing components), and operates following an Engineer-To-Order strategy in a one of a kind production context.
According to the holistic guideline described before, the company context is first considered for a preliminary analysis. After the positive qualitative results, the proper technologies for the specific requirements are identified and then an economic analysis of the selected technologies (and printers) is performed. The company context immediately appeared highly suitable for AM applications, due to the high products complexity and customization, as well as the low volumes of production: for the majority of the products realized, the buy-to-fly ratio is very high (exploiting conventional casting and molding technologies) according to the hollow structure required; considering the uniqueness of the products, the mold cost intensity is also very high, in accordance with the allocation of the mold cost to only one product manufactured Throughout the technical assessment, it has been possible to identify which technologies are feasible for company’s activities. Taking into account the main technical features, as products’ dimensions, surface finish, mechanical properties (all these data were collected through interviews directed to R&D manager), the technical database is consulted to exhaust all the available options. Not surprisingly, the output provides 15 printers belonging to SLA (6 of them) and SLS technologies (9 of them), both evaluated by the company in 2001. In the remainder of the paragraph two simulations (even though 15 simulations were originally developed according to the output of technical assessment) are shown: one for the SLA (the iPro800 printer which is the actual one adopted by the company), in order to validate the model (considering the actual adopted printers), and one for the SLS to evaluate an alternative scenario (considering the most advanced printers coming from previous step, that is the Spro140 HD by 3D Systems). It has to be noted that for SLA, the mod-el output approximate the actual cost given by the company with high accuracy (accuracy > 95%). The comparison of SLS and SLA highlights lower overall cost for SLS, with a global saving of more than 300.000 € per year (about 25% of reduction). In Figure 2 the cost structure for as-is and to-be scenarios is illustrated.
Figure 2. Economical analysis of as-is and to-be scenarios.
Material cost is lower for SLS considering that the higher waste rate of the technology is balanced with the cost per kilogram of raw material, which is roughly half compared to SLA. Machine cost is higher for SLA, and constituted the majority of the gap between the overall costs of the two technologies. This is due to the stacking parameter: SLA does not permit to stack up different products on different
layers, while SLS (that exploits powder material) ensures to fully saturate the printing chamber with different layers of products. For this reason SLA technology requires more printers to fulfill the annual demand of products than SLS. In particular, SLA requires 6 printers while SLS needs only 2. Work cost is similar for the two technologies. SLS requires more time for finishing operations, while SLA requires longer time for the setup activities.
6.2. Machinery case: comparing AM technique with traditional manufacturing The company operates in the machinery sector, manufacturing machines for yarn finishing sector. The company has a turnover over 50 million €, with several production plants in Italy, Pakistan and China and more than 400 employees. The machines are composed by an high number of pieces and the volumes for each class of machines is around 500-1000 per year. The products realized range from standard machine, sold in high volume, to personalized machines, characterized by unitary (or very small) lots. The company manifests some managerial issues related to the realization of customized machines, also due to the high price associated with the production of single components. 3D printing could help the company to manage this increasing complexity, maintaining relative low price. So, the company aims to reduce the cost of low volume productions, and reduce the time to market, primarily acting reducing the time to test of the prototypes. It has to be noticed that, only for prototyping activities, the company already uses a 3D printer (an Binder Jetting printer). In the sector the continuous innovation is considered one key competitive advantage against Chinese manufacturer, and also cost reduction is considered a valuable leverage to compete. So, considering the context and the main future company’s guidelines, some of the components associated to the customized machines appear potentially feasible for an additive manufacturing production. More in detail, some of the quantitative driver defined before can be used for evaluating the preliminary feasibility of these components. In particular, the Mold Cost Intensity is quite high, increasing the propensity for some of these parts to be realized in an additive way. Especially for 3 of them, a complete evaluation has been performed, as shown in Table 1. Table 1. Preliminary assessment synthesis. ID
Production volume [pieces/year]
P1
150
ABS
Medium
P2
100
PA 6 carbon filled
P3
100
PA 6 carbon filled
As-is material
Mold cost
Mold intensity
Cost Weigh intensity [€/kg]
11
1.400 €
0,84
848
Low
20
1.600 €
0,72
800
High
106
2.900 €
0,7
273
Complexity Weight [g]
The technical assessment is quite simple, considering the products features. The most relevant concerns the materials exploited: in fact, both the production volume and the products dimensions cannot be considered as constraints (all the professional and industrial printers satisfy these requirements). Since the 3 product was produced in two different material, there are different possibility:
Use a FDM machine Fortus 360mc, with ABSi instead of ABS and PA 12 instead of PA 6 (risky); Use a FDM machine Fortus 400mc, with ABSi instead of ABS and ULTEM 1010 instead of PA 6; Use a SLS printer with PA12 carbon filled for all the products Among the evaluated techniques, in the following analysis will be considered the most advanced, related to the Selective Laser Sintering printer. The printer price is about 420.000 € and, adding the ancillary equipment needed, the total cost is about 600.000 €. The period of deprecation is six years, coherently to the company’s policy. The high cost of the printer strictly influences the economical assessment. Compared to the analysis developed for the previous case study, in this case the output will focus on the evaluation of the breakeven point between additive technology and traditional manufacturing.
Figure 3. Cost comparison for P1.
Also considering the high ratios related to the drivers for Product 1, Figure 3 proposes an additive manufacturing convenience for production lower than 50 pieces. In fact, the cost to realize a piece through an additive production is about 40 €, while the cost associated to an injection molding process is roughly 41 €, considering batch equal to 50 pieces.
Figure 4. Cost comparison for P2.
Considering Product 2, the economical assessment suggests that the break-even point is positioned between 90 and 95 pieces. Considering that the annual volume is
about 100 pieces, the application of 3D printing appears more suitable, even if there is no full affordability.
Figure 5. Cost comparison for P3.
Product 3 is the most expensive to be realized through 3D printing, coherently with its dimension and weight. Due to the price of roughly 500 €/pieces, the break-even point is positioned between 5 and 10 pieces, far from the batch dimension (about 100 pieces). What emerged is that the more the product big, the lower is the breakeven point
7. Conclusion The majority of the existing manufacturing frameworks, that are applied for the manufacturing technology selection, stem from the past technologies, some of them dating as far back as mass manufacturing techniques. The current trend of production technology characterized by fast pace and dynamic changes is subjected to multiple variables and uncertainties. There are two points about AM that draws a lot of attention among concerning researchers in the field. First, the rather young age of AM compared with the traditional and conventional technologies and second, the ongoing process towards its full adoption as a manufacturing system in the industrial world. However, it must be noted that due to the incomplete maturity and ongoing research, many of AM’s aspects including, but not limited, to process measurement and standardization, finish surface quality, throughput rate, raw material selection, still lack enough competence to replace conventional technologies and become a widely accepted manufacturing system among industrialists. Additive manufacturing is subjected to a dual trend. So, from a non-scientific point of view manifests an overflow of available data, and the media treat every kind of possible applications and often are too enthusiasts about 3D printing, making everything seems easy; from a scientific standpoint, the literature is often not sufficient for the practical evaluation of these techniques, lacking of specific guidelines that can help non-experts attain the necessary know-how [18]. These elements create relevant gaps between company’s needs and available data and models. In order to overcome the lacks described above, this work provides an holistic model for evaluating properly the use of additive manufacturing technologies. There are at least two different directions for further development of the work: In order to define a more holistic approach to AM, it is necessary to develop more case studies and accurate tests of the guideline, in order to identify
threshold values for the described four drivers to immediately discriminate which products should be subjected to a technical and economic evaluation and which should be excluded through further analysis. Thanks to this further development, the entire evaluation process time will be cut significantly. It should be considered that, due to the rapid growth and evolution of 3D printing market and technologies, the printers database exploited for the technical feasibility evaluation, must be constantly updated. The data concerning printing speed, surface finishing quality and mechanical properties related to 3D printed products are often not available and based on assumptions of the authors.
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