A dynamic model of mass and energy flow in production systems: Material recycling and stability

A mass-energy flow model of production systems consisting of a production process, a decomposition process, a control center, natural resources, consumers, and a scrap sector, is proposed. The key to the central control process is self-regulation, e.g., as mass increases in each production level, less energy is supplied and vice versa. Saving resources through mass reutilization and decrease in waste plays an important role in the stability (local stability of an equilibrium) of the production system. Saving resources should be considered seriously, not only for economic benefits but for stability as well.