## 4 Example of Operation of Olea App  
In this section, we explore how the Olea app assists in applying three powerful decision-making methods: AHP, SAW, and VIKOR to evaluate olive trees and olive groves. To do that, we have to insert some data on the olive trees and the olive groves in the database of the Olea app. We selected some olive trees from an olive grove located in Zakynthos. Zakynthos is in the Ionian Sea, between Greece and Italy. The island covers an area of 406 km\({}^{2}\) and has a population of about 42,000 people. One of the main characteristics of the island is the existence of many olive groves. The dataset of the values of the criteria of the olive trees used in our example is presented in Table 1. In Table 1, for each tree, one can see the code of the tree, the perimeter at 1.30, the base perimeter, the height, the coordinates X and \(\Psi\), the cavitation (in Likert scale), the trunk shapes, and torsion (in Likert scale)  
When the user wants to insert new data for the criteria of an olive tree, the app will navigate to a screen where the user can input all the necessary olive grove data, as shown in Figure 1.  
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**Tree Code** & \begin{tabular}{c} **Perimeter at** \\ **1.30** \\ \end{tabular} & \begin{tabular}{c} **Base** \\ **Perimeter** \\ \end{tabular} & **Height** & \(\Psi\) & **X** & **Cavitation** & \
\begin{tabular}{c} **Trunk** \\ **Shapes** \\ \end{tabular} &
\begin{tabular}{c} **Trunk** \\ **Torsion** \\ \end{tabular} \\ \hline AMB\_KAM2 & 9.8 & 16.7 & 8.5 & 20.80993 & 37.68199 & 2 & 3 & 4 \\ \hline AMB\_KAM3 & 9.3 & 12.8 & 7.2 & 20.80999 & 37.68184 & 5 & 4 & 3 \\ \hline AMB\_KAM4 & 11.5 & 14.8 & 6.5 & 20.81018 & 37.68232 & 3 & 4 & 3 \\ \hline AMB\_KAM5 & 7.8 & 11.8 & 6 & 20.80998 & 37.68291 & 5 & 5 & 4 \\ \hline AMB\_KAM6 & 10.8 & 16.2 & 7 & 20.80988 & 37.68340 & 4 & 4 & 3 \\ \hline AMB\_KAM7 & 9.1 & 12.5 & 6.5 & 20.80950 & 37.68357 & 3 & 3 & 3 \\ \hline AMB\_KAM8 & 8.5 & 11.8 & 8.4 & 20.80995 & 37.68351 & 4 & 5 & 4 \\ \hline POR\_KOUK\_1 & 5.5 & 6.5 & 6.4 & 20.83933 & 37.70579 & 2 & 2 & 2 \\ \hline POR\_KOUK\_6 & 5.15 & 8.8 & 7 & 20.83614 & 37.72164 & 3 & 4 & 3 \\ \hline POR\_KOUK\_7 & 5.65 & 11.78 & 8 & 20.84197 & 37.71844 & 3 & 4 & 2 \\ \hline POR\_KOUK\_8 & 5.65 & 8.6 & 7 & 20.84224 & 37.71845 & 3 & 4 & 2 \\ \hline POR\_KOUK\_9 & 7.45 & 11.4 & 8 & 20.84231 & 37.71877 & 4 & 4 & 2 \\ \hline POR\_KOUK\_10 & 5.8 & 8.4 & 7.5 & 20.84246 & 37.71861 & 3 & 3 & 2 \\ \hline \hline \end{tabular}
\end{table}
Table 1: The dataset of the values of the criteria of the olive trees evaluated in the example.  
After inputting the data of the olive groves into the Olea app, by clicking on the \"Save Data and Evaluate Olive Grove\" button, the SAW method is initiated. Based on the inserted data, the SAW Value of Olive Grove is displayed in an insert report screen on the Likert scale as presented in Figure 2.  
Figure 1: Data of the olive grove.  
Figure 2: SAW Values.  
When the user selects Olive Grove comparison, the app will navigate to a screen where all Olive Groves from the Olea app's database can be displayed. The user has the option to apply filter criteria, such as the olive grove SAW limit value, the location, or if the grove is monumental. After applying the filters, the comparison can be conducted by selecting the desired olive groves to be compared with each other. Finally, after the selection, the comparison can be made with the assistance of the VIKOR method.  
Finally, the application gives the users the possibility to print a comparison report. In the final report, the ranking of the selected olive groves can be shown, with their name and the VIKOR values, as shown in Figure 3.