Below is the (anonymised) supplier network for a plant. Each circle represents a supplier. The size of the circle represents the volume of supplies purchased from that supplier. The larger the circle, the larger the purchases. The colour of the circle represents the price at which it was purchased. Red indicates a high price, yellow is neutral, and green is low.
Each sequence of lines represents a supply route along which trucks are sent to pick up supplies. The length of the lines is approximately the distance between two suppliers.
This makes it easy to spot which routes are unprofitable, which distant suppliers are not worth travelling to, and which ones to negotiate the most with.