1.3.3 Principis 3 i 4: mantenir entrades fiables i sortides saludables

These two principles are connected complementarily and are studied jointly. Inputs and outputs are subject to circulation as well. A society will disintegrate if it runs out of a necessary resource, like water or fuel. The challenge of switching from fossil fuels to more dependable energy sources highlights the issue. Since flows are inherently circular, societies that harm themselves or their surroundings by producing outputs that the local environment is unable to absorb will also perish. The effort to maintain dependable inputs of essential resources and healthy outputs, from safe water to green energy, can therefore be seen as a network flow challenge. This is one of the core focuses of the sustainability movement. The science of flow, on the other hand, expands on essential inputs to cover precise knowledge, high-quality education, wholesome food, and vigorous financial circulation.