As the number of people involved with a project increases, the number of potential person-to-person communication channels increases even faster: as the square of the number of people.

To limit this combinatorial explosion of potential communication channels, the project can be divided into subprojects, with most communication taking place between members of the same subproject. People can take on specialized roles, talking mostly to members of their subproject and to other people who have similar roles. Subproject managers can take on most of the responsibility for communicating with related subprojects.

In summary, these techniques limit the combinatorial explosion of communication channels in large projects:

• division of labor
• specialization of labor
• hierarchy