Page 71 - Materials Chemistry, Second Edition

2.3 Illustration of the Component ‘Definition of Goal and Scope’ Using an Example of Practice 55

2.3.2.5 Temporal System Boundary
Here, it is specified for which period the data holds. This is particularly important as
the production period in synopsis with the geographical system boundary provides
a background to the technical state of the art to be expected.
As an example, it is inadmissible to compare, non-commented data of 1975 from
the production in an Asian country with data of 2005 from European production.
To prevent this, strong emphasis is put on a precise specification of the temporal
system boundary.

For the comparison of packaging systems those packages are to be used
which were available on the German market in 2005. The weights and the
material composition of the examined packaging applied are expected to
appropriately reflect that.
For process data a reference time between 2002 and 2005 is valid. This
means it is aspired that the validity of the used data applies to the period
mentioned or is as near as possible.

2.3.2.6 Functional Unit and Reference Flow
This defines exactly what is to be considered for a determination of the reference
flow of the entire packing system on the basis of the defined fU.

In analogy to the UBA LCAs, the packaging necessary for the supply of 1000 l
filling material to the point-of-sale 62) is defined as fU. The reference flow
of the product system consists of the actual beverage packaging, thus, the
composite carton or PET bottle, the labels and caps as well as transport
packaging (cardboard tray, shrink-wrap and pallets) necessary for filling and
distribution of 1000 l filled goods.

2.3.2.7 Data Availability and Depth of Study
Requirements for the data are discussed in relation to the impact categories to
be included in LCIA. Thus, the consideration of the impact category ‘acidifica-
tion’ implies the quantification of emissions that contribute to acidification (see
Section 2.2.6).
As a further important aspect of data availability it is indicated that statistic
valuation is usually not possible for data from operational data acquisition, and
thus the accuracy of the data records can only insufficiently be defined.
As a result of using the UBA methodology, there are requirements concerning
the data categories to be considered. In principle, all input and output flows
of product systems that provide a relevant contribution to impact categories
according to the UBA LCA must be considered.

62) Plinke et al. (2000, S.5) and UBA (2002, S.6).