## 4 Results
### Technical Feasibility
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Material Category**} & \multirow{2}{*}{**Material**} & \multirow{2}{*}{**Reguired Surface Roughness R\({}_{a}\) (\(\mu\)m)**} & \multicolumn{2}{c}{**Actual Surface Roughness R\({}_{a}\)**} & \multirow{2}{*}{**Applicable AM Machine/Process Required**} \\  & & & & & **(\(\mu\)m) as Built** \\ \hline \multirow{4}{*}{**Steels**} & SS316L & 0.05; 12.5 & \multirow{4}{*}{13 \(\pm\) 5 [45]} & EOSINT M280/Direct Metal Laser & \multirow{4}{*}{Yes} \\  & & & & & **S**ll 280 HL/Selective Laser & \\ \cline{2-5}  & H13 & 6.3 & 24 [46] & & **S**ll 280 HL/Selective Laser & \\ \cline{2-5}  & & AlSi10 Mg & 0.4 & 8 \(\pm\) 1 [42] & & **S**ll 280 HL/SLM & \\ \cline{2-5}  & & & & & **S**ll 280 HL/SLM & \\ \cline{2-5}  & & & & & **S**ll 280 HL/SLM & \\ \cline{2-5}  & & & & & **S**ll 280 & \\ \cline{2-5}  & & & & & **S**ll 280 & \\ \hline \multirow{4}{*}{**Plasites**} & PA6 & 0.2; 6.3; 12.5 & \multirow{4}{*}{Not defined} & \multirow{4}{*}{Concept Laser Mlab causing R/SLM} & \multirow{4}{*}{Probably yes} \\  & & & & & **P**odroways ProMake P4500 & \\ \cline{1-1} \cline{3-5}  & & & & & **H**//Selective Laser Sintering (SLS) & \\ \cline{1-1} \cline{3-5}  & & & & & **Straussys uPrint SE/Tuned Deposition** & \\ \cline{1-1} \cline{3-5}  & & & & & **Modeling (FDM)** & \\ \cline{1-1} \cline{3-5}  & & & & & **P**LA 25 & 13.66 [89] & Desktop printer/FDM & No \\ \cline{1-1} \cline{3-5}  & & & & & **P**AA2200 & 0.025 & 20 [50] & EOSINT P396/SLS & Yes \\ \cline{1-1} \cline{3-5}  & & & & & **P**OM 1.7 & Not defined & Desktop printer/FDM & Probably yes \\ \cline{1-1} \cline{3-5}  & & & & & **P**QA3200 GF & 0.1 & Not defined & EOSINT P396/SLS & Probably yes \\ \cline{1-1} \cline{3-5}  & & & & & **ASA** & 12.5 & Not defined & Stratasys Fortus 300 mc/FDM & Probably yes \\ \cline{1-1} \cline{3-5}  & & & & & **H**IPS & 1.6 & Not defined & Desktop printer/FDM & Probably yes \\ \cline{1-1} \cline{3-5}  & & & & & **U**Item 9085 & 0.1 & 18.76 [51] & Stratasys Fortus 400 mc/FDM & Yes \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Comparison of required and actual minimum surface roughnesses of applicable AM machines and processes to decide on the necessity of post-processing. If a literature source for the actual surface roughness of a specific material is not identified, the necessity of post-processing is estimated according to the underlying AM process capabilities. part being manufactured [8; 10]. The necessity of post-processing was to be expected since functional interfaces require low surface roughnesses to meet high tolerances. To address this issue, common post-processing process-specific practices include shoot peening, machining (milling and turning), polishing, and vapor smoothing, for which additional resources such as labor cost and machine capabilities must be expended. Moreover, these additional production steps lead to extended lead times and can require design modifications for fixtures. To gather more detailed insights into the third most crucial technical barrier, the restriction arising from limited build chamber volumes on the size of components, Question 14 (Appendix A, Table A1) asked for the percentage of parts which fit into certain build chamber volumes ranging from less than 0.001 m\({}^{3}\) (less than 0.1 m for a single dimension of the build chamber) to more than 0.729 m\({}^{3}\) (more than 0.9 m for a single dimension). The results are displayed in Figure 3, showing that more than 20% of the corporate components fit into a build chamber volume of less than 0.001 m\({}^{3}\) and more than 80% of components into 0.729 m\({}^{3}\). Results are consequently compared to the best-in-class AM machines regarding their build envelopes and locally-based AM machines of service providers in Finland (year 2018) according to the Finnish Rapid Prototyping Association [52]. Local spare part production gains from short lead times in the sense of distributed manufacturing.