One of the main roles of System Coupling is to manage the coupled analysis. During execution, System Coupling performs a variety of one-way and two-way data transfers between coupling participants.

One-way or two-way coupling is defined relative to a coupling participant. If the participant only sends data to System Coupling or only receives data from System Coupling, then it is engaged in one-way coupling. If the same participant sends data to System Coupling (for example, heat flow) and receives data from System Coupling (for example, temperature), then it is engaged in two-way coupling.

When multiple participants execute their individual parts of a coupled analysis together, it is called a co-simulation . In co-simulation, each participant can engage in both one-way and two-way data transfers as either a source or target and perform their solutions simultaneously.