93
assigned to various components within the geometrical simulations created in
design software described in more detail in Chap. 8.
5.3.9 What Is the Standard Accuracy and Precision Level
of LCI Data?
Data requirements are variable and depend on the study’s stated goal and scope. The
study’s sponsors, along with those tasked with conducting it, set acceptable levels
of required quality (primary, aggregated, uncertainty, precision, representativeness,
etc.) appropriate to the study. Throughout the LCA’s normal iterative steps, acceptable quality standards needed to adequately describe different parts of the product
system may change.
Some parts of the system are considered as “foreground” and others “background.” Foreground systems consist of foreground processes controlled by the
decision-maker for whom the LCA is carried out. Background systems consist of
background processes on which the decision-maker exercises little or no direct
influence (Frischnecht et al. 1998).
The distinction between foreground and background process data creates a hierarchy for data collection. Generic data, common to similar product systems, requires
relatively little time, effort, and expense to gather and integrate into the background
system parts of an LCA. The more labor-intensive primary data collection effort can
then be focused on the presumably smaller and more important foreground
processes.
Designers evaluating and integrating LCA information into their workflow can
use a similar hierarchy to discern products or components with an improved profile
based on the differences in the foreground processes involved in their manufacture.
Instead of treating all life cycle inventory elements as equally important, the focus
is best concentrated on a presumably small number of unique parts of a product
system that distinguish it from similar alternative systems. The choice between two
distinct but equally durable and cost-effective fastening methods to make the
wooden table in our example above, where all other components and processes are
the same, may eventually hinge on what the data reveal about each fastening system. The background systems, wooden legs, and table top remain relatively constant, while the foreground show may show clear differences across one or more
categories.
Inventory data describe important inputs and outputs to a product system. Among
the wide range of inputs included are virgin or recycled primary mineral resources
that comprise the product, energy supply mix, and necessary ancillary service and
product inputs that fall within the system boundaries.
Primary data provide valuable numerical detail about individual process steps.
Documented product system net outputs to air, water, and soil, not captured by pollution control devices, measured and recorded at the point of release create primary
5.3 Goal and Scope Definition
assigned to various components within the geometrical simulations created in
design software described in more detail in Chap. 8.
5.3.9 What Is the Standard Accuracy and Precision Level
of LCI Data?
Data requirements are variable and depend on the study’s stated goal and scope. The
study’s sponsors, along with those tasked with conducting it, set acceptable levels
of required quality (primary, aggregated, uncertainty, precision, representativeness,
etc.) appropriate to the study. Throughout the LCA’s normal iterative steps, acceptable quality standards needed to adequately describe different parts of the product
system may change.
Some parts of the system are considered as “foreground” and others “background.” Foreground systems consist of foreground processes controlled by the
decision-maker for whom the LCA is carried out. Background systems consist of
background processes on which the decision-maker exercises little or no direct
influence (Frischnecht et al. 1998).
The distinction between foreground and background process data creates a hierarchy for data collection. Generic data, common to similar product systems, requires
relatively little time, effort, and expense to gather and integrate into the background
system parts of an LCA. The more labor-intensive primary data collection effort can
then be focused on the presumably smaller and more important foreground
processes.
Designers evaluating and integrating LCA information into their workflow can
use a similar hierarchy to discern products or components with an improved profile
based on the differences in the foreground processes involved in their manufacture.
Instead of treating all life cycle inventory elements as equally important, the focus
is best concentrated on a presumably small number of unique parts of a product
system that distinguish it from similar alternative systems. The choice between two
distinct but equally durable and cost-effective fastening methods to make the
wooden table in our example above, where all other components and processes are
the same, may eventually hinge on what the data reveal about each fastening system. The background systems, wooden legs, and table top remain relatively constant, while the foreground show may show clear differences across one or more
categories.
Inventory data describe important inputs and outputs to a product system. Among
the wide range of inputs included are virgin or recycled primary mineral resources
that comprise the product, energy supply mix, and necessary ancillary service and
product inputs that fall within the system boundaries.
Primary data provide valuable numerical detail about individual process steps.
Documented product system net outputs to air, water, and soil, not captured by pollution control devices, measured and recorded at the point of release create primary
5.3 Goal and Scope Definition