## 5 Current Trends  
Throughout the survey, various disasters are considered, such as earthquakes, floods, tsunami, drought, mudslide, hurricane, typhoon, war, and bush fires, with some work covering the possibility of secondary subsequent disaster, such as in [136; 147]. By observing Tables 15-16, it could be observed that the application of VRP in humanitarian operations largely revolves for supply and delivery problems with 73 papers, followed by evacuation problems with 32 papers and, finally, rescue operation problems with 22 papers. Figure 4 also clearly depicts this. Out of the 123 papers reviewed, only three papers solve the routing problem involving recovery phase. Two other papers addressed the disaster preparedness phase operations, while one paper looked into the mitigation phase operation. These trends in DM phases are observed in Figures 5 and 6. Meanwhile, the breakdown of DM phase according to supply and delivery, evacuation, and rescue operation is depicted in Figures 7-9, respectively. Figure 5: Breakdown of Reviewed Papers based on DM Phases. Figure 6: Selected Humanitarian Operation based on DM Phase. Figure 7: Breakdown of VRP for Supply & Delivery Operation based on DM Phase. Furthermore, only 16 papers address the slow onset disaster type, such as flood (Figures 10 and 11). Six papers addressed both rapid and slow onset disaster types, four of which applied for supply and delivery operation, while two addressed the rescue operation, as illustrated in Figures 12 and 13, respectively. Meanwhile, Figure 14 shows the break down of disaster type for evacuation operation. The rest of the papers addressed the sudden onset or rapid onset disaster, as can be seen in Figure 10. Only 28 papers could be considered as RVRP, according to the definition that is presented in Section 3.3, with a breakdown of 13 papers (46.43%) in supply and delivery operation, 12 (42.86%) in evacuation operation, as well as three (10.71%) in rescue operation addressing real world problem in a complex setting (Figure 15). Meanwhile, 79 papers addressed deterministic VRP, with one work focusing only for one vehicle. Moreover, only 26 works addressed SVRP, followed by 30 addressing DVRP, of which only seven addressed the SDVRP. The overall distribution of these model characteristics according to selected humanitarian operations could be seen in Figure 16, while Figure 17 shows the distribution of all reviewed papers against model characteristics. Surprisingly, the breakdown of the these papers shows that more rescue operation addressed both stochastic and dynamic problem (four papers), followed by supply and delivery operations with just two and evacuation operation with the remaining one paper (Figure 18). This suggests that the setting for rescue mission might be more complicated and complex, due to the life that is involved in the operation, which resonates the system to be able to operate. Figure 8: Breakdown of VRP Evacuation Operation based on DM Phase. Figure 9: Breakdown of VRP for Rescue Operation based on DM Phase. well with the study presented in [10]. Additionally, only 49 literatures addressed multi-objectives VRP, with more than half (69.39%) applied in supply and delivery operation, followed by the rescue operation (10.20%), and finally, the evacuation operation (20.41%) (Figure 19). In all three humanitarian operations, deterministic models are addressed slightly more than one-third of the papers each. This is depicted in Figures 20 and 21, as well as in Figure 22, where the summary of all three is seen in Figure 17. Additionally, the classification of papers reviewed based on deterministic VRP, SVRP, and DVRP is shown in Figures 23-25, respectively. Figure 14: Breakdown of VRP Evacuation Operation based on Disaster Type. Figure 12: Breakdown of Vehicle Routing Problem (VRP) for Supply & Delivery Operation based on Disaster Type. Figure 13: Breakdown of VRP for Rescue Operation based on Disaster Type. Figure 6:0 Selected Humanitarian Operation based on Model Characteristic.