What does Material Flow Analysis primarily track in a system?

• A. Inputs, stocks, and outputs in a system.
• B. Only energy use in production.
• C. Only recycling rates.
• D. Financial flows between processes.

Answer: (A)

Material Flow Analysis tracks the physical movement of materials within a defined system using a mass-balance approach. It primarily focuses on inputs, how much material is stored within the system (stocks), and how much leaves the system as outputs. This view lets you see where materials come from, where they accumulate, and where losses or end-of-life flows occur, which helps assess resource efficiency and opportunities for circularity. For example, in a factory you’d tally all raw materials that enter, the material held in inventory or finished products, and what exits as waste, scrap, or end-of-life recycling. While energy use, recycling rates, or financial flows can be part of broader analyses, MFA centers on the actual physical quantities moving through the system rather than costs or monetary transfers.