Material Flow Analysis - Relation To Other Industrial Ecology Methods

Relation To Other Industrial Ecology Methods

MFA is complementary to Life Cycle Assessment and Input-output models. Some overlaps between the different methods exist as they all share the system approach and to some extent the mass balance principle. The methods mainly differ in purpose, scope, and data requirements. MFA studies often cover the entire cycle (mining, production, manufacturing, use, waste handling) of a certain substance within a given geographical boundary and time frame. The level of detail of the system is adapted to the substance considered. Material stocks are considered explicitly which makes MFA suitable to tackle resource scarcity and recycling from old scrap. The common use of time series and lifetime models makes MFA a suitable forecasting tool for long-term trends in material use.

• Compared to IO analyses the number of processes considered in MFA systems is usually much lower. On the other hand mass balance ensures that flows of by-products or waste are not overlooked in MFA studies, whereas in IO tables these flows are often not listed due to their lack in economic value. In addition, physical IO models are much less common than economic ones. Material stocks are also only indirectly covered by IO analysis in form of capital accumulation. Moreover, IO models do not have an upper limit: Any given final demand can be satisfied. MFA systems on the other hand usually contain stocks of resources and hence a physical upper boundary of material turnover can be established.
• Life cycle assessments and inventories focus on the various material demands and subsequent impacts for single products, whereas MFA studies typically focus on a single material in many different products. When scaling up LCA studies to cover a whole market or sector, feedbacks on the industry, such as flows of old scrap or resource constraints should be considered, topics that are traditionally covered by MFA studies.