## 4 Results
### Robot Work Scheduling  
There are two variants of robot work scheduling (Tables 7 and 8). The first variant is that the company deploys one charging station in the warehouse and one near the production line; that is, the robots will charge for 1 h.  
If a company deploys four charging stations, this means that two charging stations will be in the warehouse and two near the production line. The robots will charge simultaneously every hour for the remaining 12 min after the processes have been carried out for 48 min. If the company deploys two charging stations for four robots, these robots will be able to move up to 202 pallets/day, which is beyond the currently required pallet quantity per hour of 180 pallets/day. The recharging of autonomous mobile robots takes only 12-15 min to reach 85%. We also use this time when calculating and using the number of robots in Tables 7 and 8. Table 7 shows that four robots move 192 pallets from the warehouse to the production line and back in 1 day. This option also satisfies the requirement for 180 pallets/day. Both methods will satisfy the requirement for a daily standard of 180 pallets/day, but the first method is more cost-effective as the company only needs to procure two charging stations compared to the second method where the company would need to procure up to four charging stations. Also, the advantage of the first method is that if the demand for the daily standard increases by approximately 20 pallets, the robots will be able to meet this demand. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Start Time**} & \multicolumn{3}{c}{**Robot**} & \multicolumn{3}{c}{**Route**} \\ \cline{2-7}  & **1** & **2** & **3** & **4** & **Warehouse–Line** & **Line–Warehouse** \\ \hline
0:00:00 & Charging & Charging & & & 0 & 0 \\
1:00:00 & 2.5 & 2.5 & Charging & Charging & 4 & 4 \\
2:00:00 & 3 & 3 & 2.5 & 2.5 & 10 & 10 \\
3:00:00 & 2.5 & 2.5 & 3 & 3 & 10 & 10 \\
4:00:00 & 3 & 3 & 2.5 & 2.5 & 10 & 10 \\
5:00:00 & 2.5 & 2.5 & 3 & 3 & 10 & 10 \\
6:00:00 & 3 & 3 & 2.5 & 2.5 & 10 & 10 \\
7:00:00 & Charging & Charging & 3 & 3 & 6 & 6 \\
8:00:00 & 2.5 & 2.5 & Charging & Charging & 4 & 4 \\
9:00:00 & 3 & 3 & 2.5 & 2.5 & 10 & 10 \\
10:00:00 & 2.5 & 2.5 & 3 & 3 & 10 & 10 \\
11:00:00 & 3 & 3 & 2.5 & 2.5 & 10 & 10 \\
12:00:00 & 2.5 & 2.5 & 3 & 3 & 10 & 10 \\
13:00:00 & 3 & 3 & Charging & Charging & 6 & 6 \\
14:00:00 & Charging & Charging & 2.5 & 2.5 & 4 & 4 \\
15:00:00 & 3 & 3 & Charging & Charging & 6 & 6 \\
16:00:00 & Charging & Charging & 2.5 & 2.5 & 4 & 4 \\
17:00:00 & 2.5 & 2.5 & 3 & 3 & 10 & 10 \\
18:00:00 & 3 & 3 & 2.5 & 2.5 & 10 & 10 \\
19:00:00 & 2.5 & 2.5 & 3 & 3 & 10 & 10 \\
20:00:00 & 3 & 3 & 2.5 & 2.5 & 10 & 10 \\
21:00:00 & 2.5 & 2.5 & 3 & 3 & 10 & 10 \\
22:00:00 & 3 & 3 & 2.5 & 2.5 & 10 & 10 \\
23:00:00 & 2.5 & 2.5 & Charging & Charging & 4 & 4 \\
00:00:00 & Charging & Charging & 2.5 & 2.5 & 4 & 4 \\ \cline{3  
Table 9 shows the costs that a company incurs for deploying robots, accessories, and service costs. The table shows that the company will spend EUR 268,000 on the deployment of robots and related technology. In Table 10 below, we have calculated the cost that the firm would have to spend on staff and associated equipment because, as things stand, four staff would not be able to meet the supply requirement of the line. Also, in the current state, the firm has only one tractor with transport frames, but this tractor is deployed in other processes, meaning that the firm would have to purchase two tractors with transport frames because this is a four-shift operation and there will be two employees working on this process in one operation. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Start Time**} & \multicolumn{4}{c}{**Robot**} & \multicolumn{2}{c}{**Route**} \\ \cline{2-5}  & **1** & **2** & **3** & **4** & **Warehouse** & **Line** & **–Warehouse** \\ \hline  
\hline \hline \end{tabular}
\end{table} 
Table 8: Robot work scheduling in case of 4 charging stations—variant 2.