Interdependence, interactions, and linkages refer how variables in a system connect, inﬂuence, and depend on one another. Scientiﬁc ﬁelds, especially the social sciences, primarily analyze how a given variable is affected by one or many others. Across-impact analysis is an approach to determine how those interactions can affect future events or a way to visualize a system, qualitatively, semi-quantitatively, and quantitatively. Anexus represents the interface of different
sectors, areas, or relatively exclusive groups, like sectors in an economy, departments in a
corporation, or disciplines in sustainable development (water, energy, etc.)Causality is the effect of some variable(s) on some other variable(s). It seeks to answer what causes the observed phenomena. Together with interdependence, interactions and linkages help us to understand small-scale causal linkages, another way to describe interconnections within a system. Most disciplines look at the small-scale structures, where most other effects are considered outside the systems. A systems approach takes many of these small-scale causal structures and combines them to generate a more complete, large-scale, and holistic picture of the entire system.