Page 45 - Materials Chemistry, Second Edition

40 3. Life cycle thinking tools: Life cycle assessment, life cycle costing and social life cycle assessment

The currently accepted definition of LCA is “compilation and evaluation of inputs, out-
puts, and potential environmental impacts of a product system throughout its life cycle,”
which typically occurs in four steps (ISO, 2006a,b), as shown in Fig. 3.1.
The first phase is the description of the goal and scope, which includes defining the
objectives of the study and setting the system boundaries. The second phase, called inventory
analysis, compiles inputs and outputs for each process in the life cycle and sums them across
the whole system. Typically, several hundreds of emissions and resources are quantified.
In the third phase, known as life-cycle impact assessment (LCIA), emissions and resources
are grouped according to their impact categories and converted to common impact
units to make them comparable. The final phase is the interpretation of the inventory and
impact assessment results in order to answer the objectives of the study (Hellweg and
Mila ` i Canals, 2014). A scheme representing the application of the LCA methodology is shown
in Fig. 3.2.
Thanks to its characteristics, LCA is also used to inform decision-makers in industry,
government, or nongovernment organizations; to select indicators of environmental perfor-
mance; and to implement eco-labeling and make environmental claims. As a decision
support tool, LCA is generally applied to a product, but also to a system or service (Tillman
and Baumann, 2004). For instance, Liamsanguan and Gheewala (2008) used LCA as a decision
support tool for environmental assessment of municipal solid waste management systems.
Ramasamy et al. (2015) used LCA as a tool to support decision making in the biopharmaceutical
industry, revealing considerations and challenges; whereas Means and Guggemons (2015) de-
veloped a framework for environmental decision-making based on LCA for commercial
buildings.
Dong et al. (2018) analyzed the need and obstacles for integrating LCA into decision
analysis, whereas Zanghelini et al. (2018) studied how multicriteria decision analysis
is aiding LCA in results interpretation. LCA is also used as a support for decision mak-
ing in the public sector; for instance, Gu erin-Schneider et al. (2018) focused on how bet-
ter to include environmental assessment in public decision-making in the case of
wastewater treatment, and Jouini et al. (2019) developed a framework for coupling
a participatory approach with LCA for public decision-making in rural territory
management.
A detailed literature review on sustainable evaluation for energy systems carried out by
Campos-Guzma ´n et al. (2019) revealed that LCA and multicriteria decision-making tech-
niques, when used in combination within the same methodological framework, can be an ef-
fective tool for sustainable evaluation. In particular, the combination of LCA and analytic
hierarchic process is often used for its simplicity and robustness for sustainable evaluation
in energy systems.

3.1.1 Goal and scope definition

The goal definition comprises the identification of the intended application, the reasons
for carrying out the study, the stakeholders involved, and how the results are intended to
be used; i.e., if they are intended to be used in comparative assertion or if they are
intended to be disclosed to the general public. The scope instead defines the dimension
and detail of the study to reach the goal. In the scope, the following items have to be
defined (ISO, 2006a):