Page 28 - Materials Chemistry, Second Edition

12 1 Introduction

The phases of LCA have been renamed, compared to earlier structures, and the
following terms are now internationally mandatory:
• Goal and Scope Definition
• Life Cycle Inventory Analysis
• Life Cycle Impact Assessment
• Interpretation.

The arrows in Figure 1.4 allow an iterative approach that is often neces-
sary (see Chapter 2). Direct applications of an LCA lie out of scope of the
standardised components of an LCA. This makes sense because, besides foreseeable
applications during the standardisation process, others were developed in practice
and have been summarised as ‘other applications’. Examples can be found in
Table 1.1.

1.3.3
Valuation – a Separate Phase?

A special status is attached to the former component valuation, 54) which has not
been assigned in the standardised structure. A valuation is always necessary when
the results of a comparative LCA are not straightforward. A trade-off of system
A against system B needs to be made when, for example, the former has lower
energy consumption, but on the other hand has releases of substances leading to
water eutrophication and to the formation of near-ground ozone: What is of greater
importance? For these decisions, subjective and/or normative notions of value
are necessary, common in daily life, for example, during purchase decisions. 55)
For this reason, a valuation based on exact scientific methods cannot be made.
Therefore, it was proposed by SETAC Europe at Leiden 1991 56) to introduce
valuation as a component of its own. This proposition was seized by UBA Berlin 57)
and by DIN-NAGUS 58) later on. However, because subjective notions of value
cannot be standardised, a methodology was developed to support the process of
conclusion. In the SETAC ‘Code of Practice’ 59) these methodological rules were
subordinated to the phase ‘Impact Assessment’. No changes were made by the
standardisation process of ISO: Methodological rules are integrated into the phase
‘Impact Assessment’ 60) (see Section 4.3). The final survey of results that leads to a
conclusion is supposed to take place in the final phase of an LCA, ‘Interpretation’ 62)
61)
(see Chapter 5).

54) In German: Bewertung.
55) DIN-NAGUS (1994), Giegrich et al. (1995), Kl¨ opffer and Volkwein (1995) and Neitzel (1996).
56) SETAC Europe (1992).
57) Schmitz, Oels and Tiedemann (1995).
58) (DIN NAGUS (1994) and Neitzel (1996).
59) SETAC (1993a).
60) ISO (2000a).
61) Grahl and Schmincke (1996).
62) ISO (2000b).