Page 108 - Materials Chemistry, Second Edition

104 5. Development and applicability of life cycle impact assessment methodologies

5.2.4.3 Time and geographical constraints
Space and time should be integrated in environmental effect aspect in LCA, whether the
original data or the evaluation result both have limitations of time and space. Additionally,
the LCA comes from the European perspective. Therefore, the impact categories included in
the prototype of the LCA reflect Europe’s environmental problems. Though the integration of
space and time can compare the different systems according to the consistent boundary def-
inition, some significant environmental impact of the systems beyond Europe are covered.

5.3 The economic assessment—LCC

Life cycle cost (LCC) is the sum of the costs throughout the whole life cycle of a product.
Theoretically, an LCC covers the entire life cycle of a product or an engineering project. The
life cycle cost assessment is an economic evaluation of a product or an engineering project
across its lifetime, which helps decision makers to choose the best investment plan, on the
basis of the least cost (Woodward, 1997; Khan et al., 2010). An LCC can be expressed as fol-
lows (Andrae et al., 2004):

LCC ¼ IC + OC + DC
where IC is initial investment cost, OC is operating cost, and DC is discarding cost.
The whole life process of a system or an equipment (planning and design, acquisition and
installation, operation and maintenance, renewal and reform, and even scrap and recycle)
will be taken into account, synthetically, which makes minimum the life cycle cost. After
building the model of an LCC, the profound influence and insignificant influence can be
gained by sensitivity analysis to provide a reference for later decisions.
In an LCC, the traditional mode, aiming at minimum acquisition expense, has been aban-
doned, which is a major breakthrough of cost decision. The new mode is not like the old way
of only thinking about short-term benefits or particular cost of equipment. The key point of an
LCC is to estimate the overall cost. For an example, the control strategy with the target for the
minimum annual burden can’t show the minimum overall cost of the equipment or the sys-
tem. The essence of an LCC is to ask decision-makers to take the whole situation into account
and plan accordingly, and mainly consider the long-term benefit. The significance of an LCC
can be shown as follows:

(1) according with the strategy of sustainable development;
(2) avoiding unnecessary loss caused by blind selection, and making decisions more scientific
and effective; and
(3) allocating resources efficiently.

5.3.1 Classification
According to different classification criteria, there are three methods to classify LCC, which
are content dependence, time dependence, and cost dependence (De Benedetto and Klemes ˇ,
2009; You et al., 2012).