## 5 Case Study and Discussion
### Case Study Data  
A 3 DP dataset related to automotive and healthcare components was applied to test the model functionality, as shown in Table 3. Thirty parts were planned and scheduled for printing, including 10 automotive parts requiring ME (parts A1-A10), 5 automotive and 5 healthcare parts requiring SLA (parts A1-A5 and H1-H5), and 5 automotive and 5 healthcare parts requiring SLS (parts A6-A10 and H6-H10). In addition, three shipping destinations with varied transportation requirements were included. Five printers were assumed available in this study: two ME printers (Sprout with a \(235\times 200\times 200\) mm build chamber and MakerBot Z18 with a \(300\times 305\times 457\) mm build chamber), two SLA printers (Formlabs with a build chamber of \(128\times 128\times 200\) mm and Replas RPS with a build chamber of \(450\times 450\times 300\) mm), and one SLS printer (sPro 60 from 3D Systems with a \(385\times 330\times 460\) mm build chamber). Then, part-related parameter data were obtained from Magics [38] and by randomly generating data, as illustrated in Table 4. Furthermore, there are also existing cost and time models in the literature (e.g., see [34]).  
\begin{table}
\begin{tabular}{c c} \hline \hline
**Parameters** & **Details** \\ \hline \hline
**Cost-Related Parameters** & \\ \hline \hline Printer cost (\$) & ME (Small 500, Large 800); SLA (Small 600, Large 1000); SLS (Small 1200, Large 1500) \\ \hline Part cost (\$) & Magics; ME: Uniform (20, 100); SLA: Uniform (50, 200); SLS: Uniform (100, 300) \\ \hline Part-holding cost (\$) & ME: Uniform (20, 100); SLA: Uniform (50, 200); SLS: Uniform (100, 300) \\ \hline Transportation cost (\$) & Uniform (5, 10) \\ \hline Production budget (\$) & 20,000 \({}^{a}\) \\ \hline Transportation budget (\$) & 20,000 \({}^{a}\) \\ \hline \hline \end{tabular}
\end{table}
Table 4: Parameters for the case study and experimental design.  
\begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline  & \multicolumn{4}{c}{**Automotive (A) \({}^{*}\)**} & \multicolumn{4}{c}{**Healthcare (H) \({}^{**}\)**} \\ \hline \hline
**CAD File** & **Length** & **Width** & **Height** & **Volume/** & **CAD File** & **Length** & **Width** & **Height** & **Volume/** \\
**1** & **(mm)** & **(mm)** & **(mm)** & **Proj. Area** & **(mm)** & **(mm)** & **(mm)** & **Proj. Area** \\ \hline
**1** & **214** & **120** & **7** & **179,760** & & & & \\
**2** & **78** & **77** & **45** & **270,270** & & & & & \\
**3** & **291** & **85** & **88** & **2,176,680** & & & & & \\
**4** & **125** & **283** & **26** & **35,375** & & & & & \\
**5** & **72** & **24** & **28** & **48,384** & & & & & \\
**6** & **311** & **48** & **44** & **656,832** & & & & & \\
**7** & **185** & **353** & **11** & **718,355** & & & & & \\
**8** & **176** & **90** & **60** & **950,400** & & & & & \\
**9** & **89** & **80** & **52** & **370,240** & & & & & \\
**10** & **135** & **146** & **33** & **19,710** & & & & & \\ \hline \hline \end{tabular}  
* Remark: \({}^{*}\) Data adapted from [PERSON] et al. [11]. \({}^{**}\) Data adapted from NIH 3D Print Exchange [44]. CAD: Computer-aided design.  
\end{table}
Table 3: Case study parts.