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Life Cycle Assessment (LCA) is an environmental management method or tool used to identify and quantify the energy and material flows of a product system, their associated environmental aspects and the related impacts on the surrounding environment (Guinée et al., 2001). LCA can be considered as both a methodological approach to measuring, and a concept for understanding, the environmental aspects of products over their life-cycle (Vigon & Curran, 1993). ISO 14040 defines LCA as the “compilation and evaluation of the

inputs, outputs and potential environmental impacts of a product system throughout its life cycle” (ISO, 2006a).

Life cycle costing (LCC) or life cycle cost analysis (LCCA) is an accounting mechanism, which aims to estimate the total costs (of a good or service) over its lifespan. Life cycle cost is defined by White and Ostwald (quoted in Woodward, 1997) as “the sum of all funds

expended in support of the item from its conception and fabrication through its operation to the end of its useful life”.

It would appear that both approaches have potential as both ‘accounting’ tools and heuristic processes for considering products’ environmental and economic performance from a whole life perspective. However, as mentioned previously in any life cycle assessment – whether it be cost, energy or environmentally focused – there is a need for clarity on definitions and assumption, in both designing a study and communicating its results. Trusty (2003, p. 2) makes the point that although quite separate conceptualisations, the approaches for life cycle environmental and life cycle costs assessments are potentially complementary. This section aims to review the conceptual and methodological context of life cycle assessment studies, of which life cycle energy and life cycle greenhouse inventory studies are subsets, and to which life cycle costing can be methodologically aligned.

Background to life cycle assessment

The first attempts at quantifying the life cycle environmental impacts of products date from

the late 1960s and early 1970s. Originating in energy analysis, LCA has developed to encompass environmental impacts in a comprehensive fashion44,45 _{(Guinée et al., 2011).}

The methodological framework for LCA was initially developed through workshops organised by SETAC46 _{in the early 1990s and was subsequently formalised in the ISO 14040}

series of standards (Guinée et al., 2001). The series currently comprises two standards that form the basis of LCA practice today, namely: ISO 14040:2006 Environmental management – Life cycle assessment – Principles and framework (ISO, 2006a); ISO 14044:2006 Environmental management – Life cycle assessment – Requirements and guidelines (ISO, 2006b).

The importance of such analyses becomes apparent when the nature of products’ life cycles is considered. For example, the production of a common everyday product, such as a laptop, involves many complex and likely dynamic value chains with many different actors feeding in to the design and production of numerous individual parts. These are in turn assembled into components, which form the building blocks of the final product. This final product is distributed and used in various contexts over its useful life, before being disassembled, recycled and disposed. The flow of materials and energy within such a product life cycle will have significant environmental impacts, but identifying and quantifying such impacts requires the modelling and calculation involved in LCA.

According to ISO 14040/44, the aforementioned standards, which describe the principles, guidelines and requirements for life cycle assessments, the process comprises four principal stages, viz.: goal and scope definition; inventory analysis; impact assessment; and interpretation. These four stages, which are conducted in an iterative fashion, are shown in Figure 14 and described below (ISO, 2006a).

44 _{Heijungset al.(1992, p. 9) observe that this evolution from an analysis tool to an assessment tool}

explains the common alternate meaning of the LCA acronym, viz., life cycle analysis.

45 _{Indeed, current trends foresee further extension to include social aspects (Guinée et al., 2011)} 46 _{Society of Environmental Toxicology and Chemistry}

Figure 14: Methodological Framework of life cycle assessment (adapted from ISO, 2006a, p. 8)

1. The goal and scope definition stage is where the initial decisions are made that determine the shape of the study to be undertaken. This is a key task, which greatly determines the ultimate outcomes of a LCA study. The goal and scope should be established in terms of what information is required, for whom, for what reason and to what level of detail. An LCA may be commissioned for a number of reasons, e.g., to identify those areas of the life cycle where significant environmental impacts arise – so- called environmental hotspots; to compare product variations or alternative processes; to make competitive comparisons in the marketplace, etc. The intended audience may be internal, e.g., process improvement, or external, e.g., customer communication, regulatory compliance. The study’s scope is defined with respect to its temporal, geographical and technological coverage; and the subject of the study is described in terms of a so-called functional unit(s), defined by ISO as “quantified performance of a

product system” (Guinée et al., 2001; ISO, 2006b), e.g., the functional unit for a paint

product could be defined as ‘1 m² surface protection for 10 years’. The use of a functional unit facilitates the comparison of alternative products.

2. Life cycle inventory analysis (LCI) involves modelling the product system and quantifying its environmental inputs and outputs. The system’s activities are described

in a series of related and interlinking flow diagrams, which are used to identify, quantify and when needed allocate the inputs and outputs associated with each activity. The level of detail required for the process descriptions (and the associated amount of data collection) is dependent on the amount of detail required by the study’s goal and scope. The input and output data is collected and stored in either generic databases or more commonly in LCA specific software such as SimaPro or GaBi. This data collection, comprising quantities of inputs and outputs associated with the functional unit, is known as the life cycle inventory (LCI) (Guinée et al., 2001; ISO, 2006b). The inventory analysis stage is closely linked to scoping, as experiences in data collection may lead to a refinement of the study’s scope, as it will clarify what data is available and its accessibility.

3. The next stage, life cycle impact assessment (LCIA) involves assessing the potential environmental relevance of the LCI data through the use of indicators. LCIA evaluates the product life cycle, on a functional unit basis, in terms of selected impact categories (ISO, 2006b). Impact categories are selected on the basis of their relevance for the study goal; examples of impact categories include: climate change, eutrophication, land use, ozone depletion, acidification, nitrification, etc. (Pennington et al., 2004).

4. The interpretation stage comprises phase of life cycle assessment in which the findings of either the inventory analysis or the impact assessment, or both, are evaluated in relation to the defined goal and scope in order to reach conclusions and recommendations (ISO, 2006b).

It is recognised that studies will not always require the full four-stage methodological framework of LCA discussed above – there are cases where the goal of the study will not require the impact assessment stage, such studies are referred to as life cycle inventory (LCI) studies, see Figure 15 below (ISO, 2006a, 2006b). The ISO 14040/44 standards can therefore provide the framework for both an LCI study, wherein for example GHG gases are

separately accounted or for a (partial) LCA study wherein the quantum of GHG is converted to the global warming potential (GWP) life cycle impact category (Finkbeiner, 2009).

Figure 15: Methodological Framework of LCA and LCI studies (adapted from ISO, 2006a, p. 8)

While acknowledging that building performance has other dimensions, quantifying building performance for those three life cycle metrics mentioned previously requires the preparation of life cycle inventories relating to cost, energy and greenhouse gas emissions

i.e., life cycle cost analysis (LCCA), life cycle energy analysis (LCEA) and life cycle inventory

analysis (LCIA) of GHG. The relevant LCA stages are therefore (i) goal and scope definition, (ii) life cycle inventory analysis and (iii) interpretation. As mentioned previously determination of the quantum of lifecycle resource use, such as energy and life cycle environmental releases, such as GHG is exactly the task for which these LCA stages were designed. The estimation of projected life cycle costs (life cycle cost inventory) requires use of life cycle costing techniques – but this too can be aligned to the three aforementioned LCA stages. The following section will review the methods of these three inventories.

3.4.2 Life cycle costs

Introduction

As mentioned on page 80, life cycle costing is an estimation of the total cost of goods over it useful life. Formalised life cycle costing (LCC) is said to have originated for use in the procurement of weapon systems in the mid 1960s within the US Department of Defense,

and thereby the wider American defence industry (Busek, 1976, p. 9; Sherif & Kolarik, 1981).

Sherif & Kolarik’s (1981) illustration of phase cost relations, shown in Figure 16 below, identifies three phases for a generic product system i.e., research & development, acquisition investment, operation & maintenance (Woodward (1997) refers to these as engineering & development, production & implementation, and operating costs respectively). It is notable and perhaps reflective of the times, that in this view end-of-life costs were not explicitly treated in the original graphic, typically such costs would now be included (e.g., Asiedu & Gu, 1998) and have been added here.

Figure 16: Generic phase cost relations for a system (derived from Sherif & Kolarik, 1981, p. 291)

The relative significance of each phase’s costs will be substantially different from product to product (and indeed even within product classes). For many products, the cost of acquisition (which in Figure 16 above include both R&D and acquisition investment) will account for the vast majority of the life cycle costs, this however would not always be the case. For example, as can be seen in Figure 10 and Figure 11 shown on pages 66 & 67, the operational phase would be more significant or even dominant in long-life products

especially those with relatively high operating costs such as buildings.

Figure 17: Alternative cost accounting methods (derived from Cole & Sterner, 2000, p. 369)

Gluch & Baumann (2004) observe a confusing range of life cycle accounting concepts. They present an overview of ten tools looking at life cycle costs and note that some have different names, but similar conceptual foundations, while other share the same name but are based on very different concepts. Cole and Sterner (2000) identify a number of different cost accounting methods which aim to reflect costs additional to acquisition as shown in Figure 17 above.

Traditionally, only the initial direct costs of acquisition would have been registered as shown by (1) on the illustration. Life cycle costing (2) expands upon this to include estimates of the future indirect costs associated with operation. Variants of life cycle costing can be further expanded to include for example the costs and revenues associated with use of a product (3)47_{. There has been substantial effort in expanding life cycle costing}

to include, for example, environmental burdens as in (4) in Figure 17. However, this is problematic, and Gluch & Baumann (2004, p. 574) observe that due to its “basis in

neoliberal economic theory LCC handles environmental aspects insufficiently”, by which

they infer that costing environmental aspects is difficult under a free market economic

model.

Consideration of externalities in such a matter is very troublesome, not least because their value is by their nature unquantifiable – how does one place a value on for example biodiversity? Thus, there are many shortcomings with using life cycle costing for environmental reasons, including (Gluch & Baumann, 2004 unless otherwise stated): conversion to monetary unit is simplistic and subjective (not to mention, likely impossible); there are ill-defined property rights in the natural world; LCC is unable to handle irreversible decisions (e.g., species extinction), as it assumes there are always alternatives; it also handle uncertainty poorly; it relies on a lot of estimated variables; cost data will have geographical, currency, and time dimensions (Ciroth, 2009); discounting rates applied to such costing inherently means inter-generation impacts such as climate change will not be afforded due consideration48 (Hampicke, 2011).

In document ANUARIO ESTADISTICO DE HIDROCARBUROS 2007 (página 73-77)