## 5 Examples of Scheduling Optimization of Apron Support Vehicles
\begin{table}
\begin{tabular}{c c c c c c c c c c c} \hline \hline \multirow{2}{*}{**Aircraft**} & \multicolumn{6}{c}{**Before**} & \multicolumn{6}{c}{**After**} \\ \cline{2-10}  & \multirow{2}{*}{**Vehicle**} & \multirow{2}{*}{\(T_{o}\)} & \multirow{2}{*}{\(T_{w}\)} & **Utilization** & \multirow{2}{*}{\(T_{t}\)} & **Vehicle** & \multirow{2}{*}{\(T_{o}\)} & **Utilization** & \multirow{2}{*}{\(T_{w}\)} & **Utilization** & \multirow{2}{*}{\(T_{t}\)} \\  & & & & **Ratio** & & & & & & **Ratio** & \\ \hline \multirow{3}{*}{3} & Re & 90 & 0 & 100\% & & & Re & 90 & 0 & 100\% & \\  & Ox & 45 & 60 & 42.9\% & 115 & Ox & 45 & 10 & 81.8\% & 90 \\  & Po & 30 & 85 & 26.1\% & & Po & 30 & 40 & 42.9\% & \\ \hline \multirow{3}{*}{4} & Re1 & 60 & 0 & 100\% & & & Re1 & 60 & 0 & 100\% & \\  & Re2 & 60 & 0 & 100\% & & & Re2 & 60 & 0 & 100\% & \\  & Ox & 60 & 30 & 66.7\% & 100 & Ox & 60 & 0 & 100\% & 60 \\  & Po1 & 20 & 50 & 28.6\% & & Po1 & 10 & 15 & 40\% & \\  & Po2 & 20 & 80 & 20\% & & & Po2 & 30 & 25 & 54.5\% & \\ \hline \multirow{3}{*}{5} & Re1 & 90 & 0 & 100\% & & & Re1 & 90 & 0 & 100\% & \\  & Re2 & 60 & 0 & 100\% & & & Re2 & 60 & 30 & 66.7\% & \\  & Ox & 75 & 30 & 71.4\% & 115 & Ox & 75 & 10 & 88.23\% & 90 \\  & Po1 & 30 & 55 & 35.3\% & & Po1 & 40 & 40 & 50\% & \\  & Po2 & 20 & 95 & 17.4\% & & Po2 & 10 & 0 & 100\% & \\ \hline \multirow{3}{*}{6} & Re1 & 60 & 0 & 100\% & & & Re1 & 60 & 30 & 66.7\% & \\  & Re2 & 60 & 0 & 100\% & & & Re2 & 60 & 30 & 66.7\% & \\ \cline{1-1}  & Re3 & 60 & 0 & 100\% & & & Re3 & 60 & 10 & 85.7\% & \\ \cline{1-1}  & Ox & 90 & 30 & 75\% & 130 & Ox & 90 & 0 & 100\% & 90 \\ \cline{1-1}  & Po1 & 20 & 50 & 28.6\% & & Po1 & 40 & 0 & 100\% & \\ \cline{1-1}  & Po2 & 20 & 80 & 20\% & & Po2 & 10 & 15 & 40\% & \\ \cline{1-1}  & Po3 & 20 & 110 & 15.4\% & & Po3 & 10 & 0 & 100\% & \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Statistics of support vehicle utilization and completion time of three operations before and after scheduling optimization. Figure 5: Change of population _fitness_ value. (**a**) 3 aircraft, (**b**) 4 aircraft, (**c**) 5 aircraft, (**d**) 6 aircraft. 1. Optimization of vehicle operation scheduling guaranteed by 3 aircraft  
For the 3-aircraft support, the support vehicle completes the support operations of the 3 aircraft in turn in the sequence of refueling \(\rightarrow\) oxygenation \(\rightarrow\) charging. From Figure 4a, it can be seen that the population _fitness_ value is stable at 90 min, and the population average value is stable at 90 min. While the population _fitness_ value remains unchanged, the reason for the change of population mean is that there are fewer support vehicles, the corresponding support process is simple and clear, and the corresponding solution process is relatively simple. It can be seen from Table 5 that the utilization rate of the refueling truck before and after optimization is 100%. After scheduling optimization, the utilization rate of the oxygenation refilling truck and power van has increased by a large margin. Specifically, the utilization rate of oxygenation refilling trucks has increased from 42.9% to 81.8% and that of power van's has increased from 26.1% to 42.9%, thereby improving the resource utilization efficiency of support vehicles and reducing the waste of resources. At the same time, the completion time of the three tasks after optimization was 90 min, that is, a saving of 25 min compared with 115 min before optimization. 2. Optimization of vehicle operation scheduling supported by 4 aircraft  
For the 4-aircraft support, XX refueling trucks support 2 aircraft, respectively, and then complete the 4-aircraft support operations in sequence in the sequence of oxygenation \(\rightarrow\) charging. Figure 4b shows that the population _fitness_ value is stable at 60 min, and the population average value is stable at 87 min. The same situation occurred here, where the population _fitness_ value remained unchanged, while the population mean value changed, for the same reason as for the 3 aircraft.