Page 67 - Materials Chemistry, Second Edition

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1. Identification of the most important results of the IA and impact assessment
2. Evaluation of the study’s outcomes, consisting of a number of the follow-
ing routines: completeness check, sensitivity analysis, uncertainty analysis
and consistency check
3. Conclusions, recommendations and reports, including a definition of the
final outcome, a comparison with the original goal of the study, drawing
up recommendations, procedures for a critical review, and the final report-
ing of the results

The results of the interpretation may lead to a new iteration round of the study,
including a possible adjustment of the original goal.

2.3 GOAL AND SCOPE DEFINITION
Section 2.2 briefly described the different steps of an LCA according to ISO 14040.
This section describes how to run an LCA goal and scope definition in practice.

2.3.1 PURPOSE OF AN LCA STUDY
The main purpose of the study — the reason why an LCA is developed — must be
clearly defined at the very beginning because it has a strong influence on further
steps. If the study is designed to compare a product with another product that has
already been submitted to an LCA, the structure, scope, and complexity of the first
product’s LCA must be similar to those of the other product so that a reliable
comparison can be made. If the aim is to analyze the environmental performance
of a product to determine its present status and to enable future improvements, the
LCA study must be organized by carefully dividing the manufacturing process into
well-defined sections or phases, to identify afterwards which parts of the process
are responsible for each environmental effect.

2.3.2 THE FUNCTIONAL UNIT

The functional unit is the central concept in LCA; it is the measure of the perfor-
mance delivered by the system under study. This unit is used as a basis for calculation
and usually also as a basis for comparison between different systems fulfilling the
same function. Table 2.1 presents examples of functional units related to the function
performed by different systems.
An important point regarding the functional unit concerns the function carried
out by the system. (When different alternatives for manufacturing products or pro-
viding service are possible, the functional unit must be clear and constantly enable
a sound comparison of the options considered.) For example, let us evaluate the
environmental impact produced by the transportation service of a person from
Barcelona to Paris, cities separated by 1000 km. The system’s function is clear:
transfer a passenger. Nevertheless, the transfer can be done by different modes,
except by ship.

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