2. Intuition Building with Center of Gravity Models
The simplest facility-location problem is the center of gravity (COG) problem. This is also a good place to start building intuition for more complicated models.
Center of gravity problems are ubiquitous in everyday life. When two children position themselves on a teeter-totter so that their different weights are in equilibrium, they are intuitively solving a two-body center of gravity problem. When a waitress loads a tray with an impressively large number of drinks and plates, and then balances the entire arrangement by positioning her hand in an unexpectedly off-center position, she is solving a center of gravity problem.
These problems come from our intuition of physics, and it is natural ...