In [an industrial ecosystem] the consumption of energy and materials is optimized, waste generation is minimized and the effluents of one process - whether they are spent catalysts from petroleum refining, fly and bottom ash from electric-power generation or discarded plastic containers from consumer products - serve as the raw material for another process.

This is a pretty new field: “industrial ecology” is considered to originate from a 1989 Scientific American article titled “Strategies for Manufacturing,” although mentions of it bubble up as far back as the early 1970s. In that 1989 article, the authors consider the implications of industrial ecology:

That quote illustrates a larger point: industrial ecology is not only a descriptive tool (quantifying flows), but it can be used as a prescriptive tool to make recommendations for system improvements. By assessing flows, industrial ecology can identify opportunities for waste reuse and reduction. This process can be scaled to look at a single car factory, to all car factories within a company, to even all car factories within a nation. Take another look at the Toyota diagram: you can see a loop (right) that indicates thermal recovery. This shows how waste is already being reused within a system.