DEMAND (VECTORS)
Customers are shown as colored circles, with a size reflecting demand quantity. Demand forces pulling the Center-of-Gravity (red circle) are shown as colored arrows (vectors) with a length refecting demand.

CENTER-OF-GRAVITY CALCULATION
All demand vectors linked together give the move direction (red arrow). The move distance (grey circle) is applied to that vector, resulting in the black arrow pointing to the Center-of-Gravity position to be evaluated.