1. Systems theory views organizations as sets of interacting units that respond to environmental pressures to achieve and maintain goal states. 2. Public relations is part of an organization's adaptive subsystem, taking a strategic role in open systems to help the organization adjust to changes in its environment. 3. Stakeholder theory defines stakeholders as groups that can affect or be affected by an organization, and argues that organizations must have reciprocal rather than adversarial relationships with stakeholders to maintain legitimacy.