Civil Engineering Reference
In-Depth Information
Goal and scope
definition
(ISO 14041)
Direct application
Product development and
improvement
Strategic planning
Public policy
Marketing
Other
Inventory
analysis
(ISO 14041)
Interpretation
(ISO 14043
Impact
assessment
(ISO 14042)
3.1
LCA phases.
and calculation procedures to quantify relevant inputs and outputs of a product
system. These inputs and outputs include the use of resources, emissions to
air, water and soil, and waste generation associated with the system. The
inventory analysis is supported by a process tree (process diagram, flow tree)
which defines the phases in the life cycle of a product, (Fig. 3.2). Each of the
different phases can be made up from different unit processes, i.e. production
of different kinds of raw materials to be combined in the material production
phase. The different phases are often connected by transport processes. The
data regarding material and energy consumption, waste and emissions have
to be collected from all unit processes in a product life cycle. The data can
be site specific (from specific companies, specific areas or specific countries)
or more general, from more general sources like trade organizations or public
surveys. For detailed LCa studies, site-specific data should be used. The
average data (from trade organizations, from previous investigations of the
same or similar product, etc.) may be used for conceptual or simplified LCa
(Jensen et al., 1997). However, this step is often the most work-intensive
part of an LCa, especially if the site-specific data are needed for all the unit
processes in the life cycle.
impact assessment is the third phase in an LCa, in which the potential
environmental impacts of the modeled system are evaluated. This step
consists of three mandatory elements: (1) selection of impact categories,
category indicators and characterization models, (2) classification and (3)
characterization.
