# Efficient Metaheuristics for the Mixed Team Orienteering Problem with Time Windows
## 7 Experimental Results
### Results  
All computations have been executed on a personal computer Intel Core i3 with 2.30 GHz processor and 4 GB RAM. Our tests aim at comparing the presented ILS and SA algorithm. The algorithms are compared with respect to the obtained profit and the execution time. Mostly prefered solutions are those associated with high profit values (higher profit values denote higher quality solutions) and reduced execution time (as this denotes improved suitability for real-time applications). Both algorithms have been coded in C++. The numberOffterations parameter in ILS takes the values 100, 200, 400 and 800 and the corresponding results are reported as ILS\({}_{100}\), ILS\({}_{200}\), ILS\({}_{400}\) and ILS\({}_{800}\). We use the same parameter numberOffterations(=numSchemes \(\cdot\) schemeIt) for denoting the total number of \begin{table}
\begin{tabular}{c c c c c c} \hline \hline  & \multirow{2}{*}{**Percent**} & \multicolumn{3}{c}{**Time Window (Min)**} & \multirow{2}{*}{**Visiting Time (Min)**} & \multirow{2}{*}{**Profit**} \\ \cline{3-3} \cline{5-6}  & & **Weekdays** & & & \\ \hline \multirow{5}{*}{POIs} & 20\% & all day & all day & 15–30 & 15–30 \\  & 20\% & 540–960 & closed & 30–60 & 30–60 \\  & 20\% & 540–960 & 540–960 & 60–120 & 70–100 \\  & 20\% & 840–1140 & 840–1140 & 30–60 & 30–60 \\  & 20\% & 480–780 & closed & 30–60 & 30–60 \\ \hline \multirow{5}{*}{Scenic routes} & 25\% & all day & all day & & 10–50 \\  & 25\% & 540–960 & 540–960 & \multirow{2}{*}{N/A} & 10–50 \\  & 25\% & 480–840 & 480–840 & & 10–50 \\ \cline{1-1}  & 25\% & 540–960 & closed & & 10–50 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Points of interest (POI) and scenic route parameters. iterations in SA. The parameters maxTemperature and coolingFactor are always set equal to 10 and 0.5, respectively. These values have been chosen due to providing marginally better results, as demonstrated experimentally. Also, they guarantee that a large part of the search space is searched. The other parameters of SA are set to the following values: numberOffterations = 0.5 and 1 million, coolItFactor = 0.8,0.5 and 0.25, and the schemelFFactor = 8 and 10. We use the notation SA_numberOfIterations_coolItFactor_schemelFFactor for denoting the results for the SA for specific values of the SA parameters; for example, for numberOffterations equal to 0.5 million, coolItFactor equal to 0.8 and schemelFactor equal to 8, the results obtained are indicated with SA_0.5M_0.8_8. Each one of the proposed algorithms is executed 5 times for each instance. Table 2 illustrates the experimental results compiled from the executed algorithms for each value of the parameters. The results obtained are averaged with respect to the number of requested walks. In more detail, each algorithm with its associated parameter values is shown in the first column. The next four pairs of columns present the experimental results obtained for instances requesting 1, 2, 3 and 4 walks, respectively. Each pair of columns shows the average profit obtained and the average execution time of each algorithm for the 5 executions of each instance asking for a specific number of walks. So, the average profit and execution time (in ms) for instances requesting 1 walk (pref100-pref199) are given in the first pair of columns of Table 2, while the average results obtained for 2 (pref200-pref299), 3 (pref300-pref399) and 4 (pref400-pref499) walks are given in the second, third and fourth pair of columns of Table 2, respectively. Based on the experimental results, we can easily conclude that increasing the algorithms' execution time, _i.e._, increasing the allowed number of iterations, improves the solutions' quality marginally. To see this, consider first the ILS algorithm. The average profit for 200 iterations is higher than that for 100 iterations by less than 0.7% for all number of walks. The same holds when comparing the results for 400 and 200 iterations as well as for 800 and 400 iterations.