The invention relates to a computer-implemented surveillance method for surveilling an area of interest using a set of drones, the surveillance method including monitoring a number of operational drones among the set of drones. If a change in the number of operational drones is detected, performing a segmentation step for segmenting the area of interest into N sub-areas, N being the current number of operational drones; and performing an affectation step for affecting each operational drone to a respective sub-area for surveilling said sub-area.