## 5 Case Study
### Results and Comparative Analysis  
The optimal solutions were obtained using the methodology outlined in Section 4, with findings presented in Table 6. The optimal resolution involves the deployment of two vehicles: a 1-ton capacity forklift and a 3-ton capacity forklift. Specifically, a forklift with a 1-ton load capacity follows the route from the logistics center to 3 to 1 and then to the processing center, while the 3-ton forklift travels from the logistics center to collection points 2, 4, 5, and 6 before reaching the processing center. The path planning diagram is illustrated in Figure 9. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Vehicle Type** & **Route** & **Z1** & **Z2** \\ \hline
1.0T forklift & S-3-1-E & & 41.95 & 10.54 \\
3.0T forklift & S-2-4-5-6-E & & 41.95 & 10.54 \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Details of the optimal result. Figure 8: Location information of collection points (km). \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{**Vehicle Type**} & \multicolumn{4}{c}{**Colllection Points**} & \multirow{2}{*}{**E**} \\ \cline{2-2} \cline{4-7}  & & \(\mathbf{i}_{1}\) & \(\mathbf{i}_{2}\) & \(\mathbf{i}_{3}\) & \(\mathbf{i}_{4}\) & \(\mathbf{i}_{5}\) & \(\mathbf{i}_{5}\) \\ \hline S & 0 & 0.6 & 0.5 & 0.4 & 1.0 & 1.2 & 1.3 \\ \(i_{i}\) & 0.6 & 0 & 0.3 & 0.5 & 0.4 & 0.7 & 0.8 & 1.1 \\ \(i_{z}\) & 0.5 & 0.3 & 0 & 0.6 & 0.2 & 0.5 & 0.7 & 1.3 \\ \(i_{3}\) & 0.4 & 0.5 & 0.6 & 0 & 0.7 & 0.4 & 1.1 & 1.2 \\ \(i_{4}\) & 1.0 & 0.4 & 0.2 & 0.7 & 0 & 0.3 & 0.9 & 1.3 \\ \(i_{5}\) & 1.2 & 0.7 & 0.5 & 0.4 & 0.3 & 0 & 0.6 & 1.0 \\ \(i_{6}\) & 1.3 & 0.8 & 0.7 & 1.1 & 0.9 & 0.6 & 0 & 0.9 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Location information table of collection points (km). To evaluate the effectiveness of the proposed model concerning safety objectives, we compared the optimal solutions derived from the safety-efficiency scheduling model with those obtained from a cost-focused approach. For this analysis, we selected the top nine solutions based on their cost effectiveness to serve as benchmarks, allowing for a comprehensive assessment of potential safety risks that may be overlooked in cost-driven scenarios. Table 7 presents Solution 1 as the optimal configuration that balances safety, cost, efficiency, and environmental considerations. This option prioritizes safety and minimizes potential safety risks while maintaining good cost effectiveness. The relatively high level of safety services under option 1 demonstrates that the option is able to ensure the safety of the hazardous waste transport process while still keeping costs under control. Although the target value for cost-effectiveness is slightly lower than some cost-driven options, it is a superior overall performer and is effective in avoiding the long-term risks associated with neglecting safety. In contrast, Solutions 2 to 10, which are based solely on cost objectives, lack safety considerations, leading to a less comprehensive evaluation. Further analysis involved inputting the results of Solutions 2 to 10 into Equation (3) to derive the health and safety service level values for each solution, quantifying their performance in terms of Health, Safety, and Environment management. In terms of the data, these options have better cost-effectiveness target values, meaning that they perform well in cost control and are able to minimize transport costs, storage costs and other management costs. However, these cost-focused optimized options have relatively low security service levels.