Boundary

A boundary is a conceptual limit for the analysis of a system.

For example, we can say all systems exist within the universe as a system of physical laws, but constantly accounting for that may be irrelevant to the focus or purpose of an analysis and as such end up cluttering it without adding any meaningful context.

Boundaries are important for analysis because they don't dismiss justification, improving concision while doing so explicitly. This means they don't silently omit overarching systems and interactions.