SiFAs communicate by sending each other messages. Each agent can communicate directly with any other agent without the need for an arbitrator. The communication language used is based on KQML (Knowledge Query and Manipulation Language) [Finin et al.].
The current state of the design resides on a blackboard structure which is accessible to all agents. Even thought agents exchange messages directly, design data flows thorough the blackboard. This is shown in figure 3.3.
Figure 3.3: Communication and data flow