10 07 29 Master thesis Juliana Leon - e-Waste. This guide

2.3.1 Definitions
The following important terms for a MFA are defined according to the “Practical
Handbook of Material Flow Analysis” by Brunner and Rechberger (2004)
Material
The term material includes substances and goods. Substances are defined as the
elemental components of which a thing consists, whereas goods are entities of
matter made up of one or several substances.
Process
A process is defined as the transformation, transport, or storage of materials.
Processes are symbolized as rectangular boxes while a smaller box within a
“process” box symbolizes the “stock” of a process.
Flow
A flow or mass flow rate is defined as the rate of mass per time from a specific
material that flows between a “process of origin” and a “process of destination”. The
physical unit of a flow may, thus, be given in units of tons/year or kg/day.
Transfer coefficient
When a process has multiple outputs, transfer coefficients describe the partitioning of
a material into different flows.
2.3.2 System definition
The lifecycle of an electronic device can be divided into the production, use, and endof-life
phases. The system that will be analysed in this thesis focuses on the
processes carried out in the end-of-life phase (Figure 5).
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