During world war ii, the british royal air force estimated the density of bullet holes on differnt sections o fplanes returning to base from aerial sorties. their goal was to use this information to

Their goal was to use this information to determine which plan sections most needed additional protective shields.
There are many crucial part of the plan that should be prioritized for the protective shields, such as the tank that contain the fuel of the plane or the machinery that played a crucial role to keep the engine running.

The goal was to determine which plan sections that needs the most of the additional protective shield  which plan sections most needed additional protective shields. They found that the highest density of holes was on the wings and concluded that the wings should be reinforced but they made a mistake in doing so.