Page 349 - Materials Chemistry, Second Edition

5.2 The Phase Interpretation According to ISO 333

• Contributions of life cycle sections, for example, single unit processes or groups
of unit processes (e.g. transports or energy production).
The deduction of significance according to the same standard (Section 4.5.2.3) is
carried out with the help of the following four types of information:
• The results of the already finished phases of life cycle inventory and LCIA;
• Elements of the methodological approach, for example, allocation rules and
system boundary in the inventory, impact categories and models (characterisation
factors) of the impact assessment;
• Value choices applied in the study on the basis of the goal of the study and
applied in the optional steps of grouping/weighting and normalisation in the
phase impact assessment;
• Role and responsibility of interested parties and results of the critical review. 11)

Now follows a determination of consistency of results not explicitly described by
the standards, but noted in ISO 14044, Section 4.5.2.3:

When the results from preceding phases (LCI, LCIA) have been found to meet the
demands of the goal and scope of the study, the significance of these results shall be
determined.

5.2.4
Evaluation

Evaluation 12) according to the standards aims to enforce trust into the reliability of
results of an LCA and into significant parameters. A further intent is to provide a
clear and comprehensible overview of the results of the study.
The use of the following three techniques shall be considered:
• Completeness check
• Sensitivity check
• Consistency check.

The completeness check relates to all relevant information especially to the provision
of ‘significant parameters’ (Section 5.2.3). In case of gaps, the inventory or the
impact assessment should be repeated with optimised data in the sense of an
iterative approach. As an alternative, the goal and scope can be adapted to the
information provided. This implies that in most cases expectations need to be
lowered in order to provide consistency.
The sensitivity check is probably the most frequently applied quantitative technique
for evaluation. According to ISO 14044, it is mandatory if a choice between several
allocation rules is possible.

11) As the critical review includes the interpretation phase, only intermediate results of an interactive
review are possible.
12) Evaluation should not be confused with valuation. The former is orientated towards critical
scientific quality standards.