To efficiently realize a specified goal in a distributive fashion, there needs to be an appropriate "division of labor." This is true for distributive algorithms that take advantage of the concurrent features of the new generation of computers. This is true in the design of a complex organization intended to realize a specified goa1. The problem is to determine what the appropriate division of labor is. Here, a geometric characterization of all possible divisions of labor, or communication networks, is given. It is illustrated how this characterization can be used to design the communication networks.