Article; Supply Chains Are Us https://thereader.mitpress.mit.edu/supply-chains-are-us/
Supply chains are large industrial systems. They are composed of heterogeneous elements, such as ships, aircraft, trains, and trucks, but also systems of labor, information, and finance that build them and connect them together. Usually the goods flow in one direction and money flows in the opposite direction. Their physical substrates are themselves industrial products, relying on ships, trucks, cranes, fossil fuels, and electric power, tied together by skilled human operators, supervisors, managers, and other industrial roles.