# Reconfiguration Decision-Making of IoT based Reconfigurable Manufacturing Systems
## 7 Conclusions  
Various types of manufacturing systems have been tried to realize flexible manufacturing. RMS is one of the solutions to enable flexibility. This study proposed an algorithm for reconfiguration decision-making of RMS with IoT sensors. Generally, machines in RMS can change their available tasks through reconfiguration. A RMS requires reconfiguration to offer flexibility. Therefore, managers of RMS need to make reconfiguration decisions efficiently. To make a good decision, it is required to collect various information in and out of machines. This study proposed a variable neighborhood search (VNS) based reconfiguration decision-making algorithm to create a reconfiguration plan with the use of \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Number of** **Processes**} & \multirow{2}{*}{**Situation**} & **Number of** **Satisfied** & **Performance Ratio** & \multirow{2}{*}{**Total Cost**} & **Calculation** \\  & & **Satisfied** & **Compared without** & & **Time (sec)** \\  & & **Demands** & **Reconfiguration (\%)** & & \\ \hline \multirow{4}{*}{3} & 1 & 28.85 & 80.99 & 1781.2 & 82.14 \\  & 2 & 32.31 & 90.71 & 1143.4 & 86.59 \\  & 3 & 27.71 & 77.80 & 2897.9 & 74.90 \\  & 4 & 31.13 & 87.40 & 2917.7 & 81.27 \\  & 1 & 28.06 & 78.77 & 2838.0 & 107.48 \\  & 2 & 28.28 & 79.41 & 2889.2 & 100.60 \\  & 3 & 23.24 & 65.25 & 2959.3 & 108.03 \\  & 4 & 26.96 & 75.69 & 3127.6 & 92.81 \\ \hline \hline \end{tabular}
\end{table} 
Table 8: Experimental result according to the number of processes and reconfigurable situations. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Rule**} & \multirow{2}{*}{**Situation**} & **Number of** **Satisfied** & **Performance Ratio** & \multirow{2}{*}{**Total Cost**} & **Calculation** \\  & & **Demands** & **Reconfiguration (\%)** & & **Time (sec)** \\ \hline \multirow{4}{*}{FIFO} & 1 & 27.33 & 83.35 & 2082.70 & 93.56 \\  & 2 & 24.58 & 74.95 & 2000.37 & 95.41 \\  & 3 & 23.58 & 71.91 & 2928.02 & 90.73 \\  & 4 & 29.02 & 88.49 & 3022.61 & 85.06 \\  & 1 & 27.71 & 82.13 & 2083.00 & 92.93 \\  & 2 & 26.48 & 78.51 & 1992.40 & 96.31 \\  & 3 & 24.21 & 71.78 & 2927.75 & 90.36 \\  & 4 & 29.03 & 86.04 & 3022.59 & 84.07 \\  & 1 & 30.32 & 75.18 & 2080.55 & 97.94 \\  & 2 & 39.83 & 98.75 & 2056.09 & 89.06 \\  & 3 & 28.64 & 71.01 & 2929.95 & 93.30 \\  & 4 & 29.09 & 72.13 & 3022.80 & 91.99 \\ \hline \hline \end{tabular}
\end{table} 
Table 9: Experimental result according to scheduling rule and reconfigurable situations. an IoT sensor-based data acquisition system for RMS. We used a simulation approach to evaluate a reconfiguration plan and VNS to find an improved solution. Through the simulation experiment in various environments, the performance of the proposed algorithm was verified. In the experiment, the algorithm proposed in this study delivered excellent performance in reconfiguration situations. As a result of the simulation experiments, the advantages of IoT sensor applications outweighed the cost of the sensors. IoT sensors make it possible to respond quickly to an unpredicted situation and rapid ramp-up. The simulation experiment revealed that the suggested system suppressed the performance degradation made after reconfiguration at a stable level in various scheduling rules. This study proposed a reconfiguration decision-making algorithm for RMS, which reflects the characteristics of the flow shop with reconfiguration functions. It applied realistic assumptions in the ramp-up process and recognition of the situation. It is expected that the proposed algorithm can be applied to an actual factory. However, in this study, reconfiguration was limited to machines. In the future, a reconfiguration decision-making algorithm that covers jigs, fixtures, conveyors, and tools will be researched. Additionally, the following research will be conducted on other different reconfiguration situations than the situations set in this study. In this way, it is expected to develop an applicable reconfiguration decision-making system for a RMS.