Page 129 - Materials Chemistry, Second Edition

112 LIFE CYCLE ASSESSMENT HANDBOOK

The required level of aggregated data should be specified (as guided by
the study's goal), for example, whether data are representative of one process
or of several processes. Figure 5.2 depicts the possible variations to aggre-
gate processes (steps 2 through 11). Step 1 indicates no aggregation (a single
process); step 12 is the complete cradle-to-grave LCI, the ultimate form of
aggregation.

5.4 Private Industrial Data

Complete and thorough inventories often require using proprietary data that
are provided by either the manufacturer of the product, upstream suppliers,
or vendors, or the LCA practitioner performing the study. Confidentiality
issues are not relevant for life-cycle inventories conducted by companies using
their own facility data for internal purposes. However, the use of proprietary
data is a critical issue in inventories conducted for external use and whenever
facility-specific data are obtained from external suppliers for internal studies.
Consequently, current studies often contain insufficient source and documen-
tation data to permit technically sound external review. Lack of technically
sound data adversely affects the credibility of both the life-cycle inventories
and the method for performing them. An individual company's trade secrets
and competitive technologies must be protected. When collecting data (and
later when reporting the results), the protection of confidential business infor-
mation should be weighed against the need for a full and detailed analysis or
disclosure of information. Some form of selective confidentiality agreements
for entities performing life-cycle inventories, as well as formalization of peer
review procedures, is often necessary for inventories that will be used in a
public forum. Thus, industry data may need to undergo intermediate confi-
dential review prior to becoming an aggregated data source for a document
that is to be publicly released.
Examples of private industry data sources include independent or internal
reports, periodic measurements, accounting or engineering reports or data
sets, specific measurements, and machine specifications. One particular issue
of interest in considering industrial sources, whether or not a formal public
data set is established, is the influence of industry and related technical associ-
ations to enhance the accuracy, representativeness, and up-to-datedness of the
collected data. Such associations may be willing, without providing specific
data, to confirm that certain data (about which their members are knowledge-
able) are realistic.

5.5 Public Industrial Data

Technical books, reports, conference papers, and articles published in technical
journals are a good source for information and data on industrial processes and