"Perrow proposed that systems in general could be described by two dimensions called coupling and interactiveness." #readingToday

Perrow proposed that systems in general could be described by two dimensions called coupling and interactiveness, respectively (see Figure 5.1). Coupling describes the degree to which subsystems, functions, and components are connected or depend upon each other; the degree of coupling can range from loose to tight. Interactiveness describes the degree to which events in the system develop in ways that are expected, familiar, and visible, or whether they develop in ways that are unexpected, unfamiliar, and invisible. The degree of interactiveness can range from linear to complex interactions, respectively.

The ETTO Principle, Erik Hollnagel