Product Environmental Life-Cycle Assessment Using Input-Output Techniques

Life-cycle assessment (LCA) facilitates a systems view in environmental evaluation of products, materials, and processes. Life-cycle assessment attempts to quantify environmental burdens over the entire life-cycle of a product from raw material extraction, manufacturing, and use to ultimate disposal. However, current methods for LCA suffer from problems of subjective boundary definition, inflexibility, high cost, data confidentiality, and aggregation.
This paper proposes alternative models to conduct quick, cost effective, and yet comprehensive life-cycle assessments. The core of the analytical model consists of the 498 sector economic input-output tables for the U.S. economy augmented with various sector-level environmental impact vectors. The environmental impacts covered include global warming, acidification, energy use, non-renewable ores consumption, eutrophication, conventional pollutant emissions and toxic releases to the environment. Alternative models are proposed for environmental assessment of individual products, processes, and life-cycle stages by selective disaggregation of aggregate input-output data or by creation of hypothetical new commodity sectors. To demonstrate the method, a case study comparing the life-cycle environmental performance of steel and plastic automobile fuel tank systems is presented.     

Environmentally Conscious Product Design: A Collaborative Internet-based Modeling Approach

This paper proposes a computer-based method for providing product designers with real-time environmental impact assessment. In this concurrent modeling approach, environmental experts build life-cycle models, define their interfaces, and publish them as distributed objects on the Internet. Traditional designers integrating these objects into their design models have access to the impact assessment methods provided by the environmental expert. In this paradigm, the focus shifts from providing techniques that let non-expert designers perform life-cycle impact assessments to tools that facilitate timely communication and information transfer between designers and appropriate environmental experts. Establishing real-time communication between the product design models and the environmental life-cycle models is the primary focus of this paper. Methods for establishing and maintaining the interaction between life-cycle and product design models are described. A beverage container design example illustrates how this collaborative approach can use environmental and traditional design goals to determine effective tradeoffs between design alternatives.     

LiSET: A Framework for Early‐Stage Life Cycle Screening of Emerging Technologies

While life cycle assessment (LCA) is a tool often used to evaluate the environmental impacts of products and technologies, the amount of data required to perform such studies make the evaluation of emerging technologies using the conventional LCA approach challenging. The development paradox is such that the inputs from a comprehensive environmental assessment has the greatest effect early in the development phase, and yet the data required to perform such an assessment are generally lacking until it is too late. Previous attempts to formalize strategies for performing streamlined or screening LCAs were made in the late 1990s and early 2000s, mostly to rapidly compare the environmental performance of product design candidates. These strategies lack the transparency and consistency required for the environmental screening of large numbers of early‐development candidates, for which data are even sparser. We propose the Lifecycle Screening of Emerging Technologies method (LiSET). LiSET is an adaptable screening‐to‐LCA method that uses the available data to systematically and transparently evaluate the environmental performance of technologies at low readiness levels. Iterations follow technological development and allow a progression to a full LCA if desired. In early iterations, LiSET presents results in a matrix structure combined with a “traffic light” color grading system. This format inherently communicates the high uncertainty of analysis at this stage and presents numerous environmental aspects assessed. LiSET takes advantage of a decomposition analysis and data not traditionally used in LCAs to gain insight to the life cycle impacts and ensure that the most environmentally sustainable technologies are adopted.     

Recent Advances in Design for Environment at Motorola

Motorola is a large electronics company that uses design for environment (DfE) t o address our customers' environmental needs. In working to integrate environmental considerations into product design, Motorola has encountered new challenges in product design, and as a result has had to develop new frameworks and employ new analytical tools. This article describes those challenges and Motorola's efforts to date. The examination of how products are designed in Motorola led to the realization that there are distinct phases in design: concept development, detail design, and prototype manufacture. In the earlier phases where the greatest flexibility for product reconfiguration exists, there is the least amount of detailed information available for use in making environmental assessments. In an effort to match the data availability to the environmental assessment needs, Motorola developed a tiered approach to DE using a matrix-based abridged life-cycle assessment (LCA) in the concept development stage, a scoring system based in part on multiattribute value theory in the detail design stage, and potentially full-scale life-cycle assessment in the prototype manufacturing stage.     

Weighted matrices as product life cycle assessment tools

Experience demonstrates that comprehensive life cycle assessments (LCAs) for complex manufactured products are too data-intensive and too costly, and the results too uncertain, to be useful as regular tools for the product designer. In their place, streamlined LCAs, preserving the concepts of evaluating all product life stages and a range of environmental concerns yet doing so in semiquantitative and much more efficient ways, are becoming common. They suffer, however, from an inability to prioritize and emphasize the most important life stages and environmental concerns. This paper presents a methodology for using weighted matrices to accomplish this latter goal while preserving much of the straightforward approach and efficient information display attributes typical of unweighted, streamlined LCAs. The techniques are demonstrated by performing assessments on generic automobiles of the 1950s.     

Sustainability Constraints as System Boundaries: An Approach to Making Life-Cycle Management Strategic

Sustainable management of materials and products requires continuous evaluation of numerous complex social, ecological, and economic factors. A number of tools and methods are emerging to support this. One of the most rigorous is life-cycle assessment (LCA). But LCAs often lack a sustainability perspective and bring about difficult trade-offs between specificity and depth, on the one hand, and comprehension and applicability, on the other. This article applies a framework for strategic sustainable development (often referred to as The Natural Step (TNS) framework) based on backcasting from basic principles for sustainability. The aim is to foster a new general approach to the management of materials and products, here termed "strategic life-cycle management". This includes informing the overall analysis with aspects that are relevant to a basic perspective on (1) sustainability, and (2) strategy to arrive at sustainability. The resulting overview is expected to help avoid costly assessments of flows and practices that are not critical from a sustainability and/or strategic perspective and to help identify strategic gaps in knowledge or potential problems that need further assessment. Early experience indicates that the approach can complement some existing tools and concepts by informing them from a sustainability perspective-for example, current product development and LCA tools.     

Life-Cycle Assessment: Constraints on Moving from Inventory to Impact Assessment

Life-cycle assessment (LCA) is a technique for systematically analyzing a product from cradle-to-grave, that is, from resource extraction through manufacture and use to disposal. LCA is a mixed or hybrid analytical system. An inventory phase analyzes system inputs of energy and materials along with outputs of emissions and wastes throughout life cycle, usually as quantitative mass loadings. An impact assessment phase then examines these loadings in light of potential environmental issues using a mixed spectrum of qualitative and quantitative methods. The constraints imposed by inventory's loss of spatial, temporal, dose-response, and threshold information raise concerns about the accuracy of impact assessment. The degree of constraint varies widely according to the environmental issue in question and models used to extrapolate the inventory data. LCA results may have limited value in two areas: (I) local and/ortransient biophysical processes and (2) issues involving biological parameters, such as biodiversity, habitat alteration, and toxicity. The end result is that impact assessment does not measure actual effects or impacts, nor does it calculate the likelihood of an effect or risk Rather, LCA impact assessment results are largely directional environmental indicaton. The accuracy and usefulness of indicators need to be assessed individually and in a circumstance-specific manner prior to decision making. This limits LCAs usefulness as the sole basis for comprehensive assessments and the comparisons of alternatives. In conclusion, LCA may identify potential issues from a systemwide perspective, but more-focused assessments using other analytical techniques are often necessary to resolve the issues.     

Life Cycle Approach in the Procurement Process: The Case of Defence Materiel (9 pp)

Goal, Scope and Background Procurement in public and non-public organisations has the potential to influence product development towards more environmentally friendly products. This article focuses on public procurement with procurement in Swedish defence as a special case. In 2003, public procurement in Sweden was 28% of the GDP. In the Swedish defence sector the amount was 2% of the GDP. The total emissions from the sector were of the same order of magnitude as from waste treatment (2% of Sweden's emissions). According to an appropriation letter from the Ministry of Defence in 1998, the Swedish Armed Forces (SAF) and the Swedish Defence Materiel Administration (FMV) are required to take environmental issues into consideration during the entire process of acquiring defence materiel. Environmental aspects are considered today, but without a life-cycle perspective. - The aims of this article are to recommend suitable tools for taking environmental concerns into account, considering a product's life-cycle, in the procurement process for defence materiel in Sweden; to make suggestions for how these tools could be used in the acquisition process; and to evaluate these suggestions through interviews with actors in the acquisition process. The procurement process does not include aspects specific to Swedish defence, and it is therefore likely to be comparable to processes in other countries. Methods The method involved a study of current literature and interviews with various actors in the acquisition process. The life cycle methods considered were quantitative Life Cycle Assessments, a simplified LCA-method called the MECO method and Life Cycle Costing (LCC). Results and Discussion Methodology recommendations for quantitative LCA and simplified LCA are presented in the article, as well as suggestions on how to integrate LCA methods in the acquisition process. We identified four areas for use for LCA in the acquisition process: to learn about environmental aspects of the product; to fulfil requirements from customers; to set environmental requirements and to choose between alternatives. Therefore, tools such as LCAs are useful in several steps in the acquisition process. Conclusion From the interviews, it became clear that the actors in the acquisition process think that environmental aspects should be included early in the process. The actors are interested in using LCA methods, but there is a need for an initiative from one or several of them if the method is to be used regularly in the process. Environmental and acquisition issues are handled with very little interaction in the controlling and ordering organisation. An integration of environmental and acquisition parts in these organisations is probably needed in order to integrate environmental aspects in general and life-cycle thinking in particular. Other difficulties identified are costs and time constraints. Recommendation and Perspective In order to include the most significant aspects when procuring materiel, it is important to consider the whole life-cycle of the products. Our major recommendation is that the defence sector should work systematically through different product groups. For each product group, quantitative, traditional LCAs or simplified LCAs (in this case modified MECOs) should be performed for reference products within each product group. The results should be an identification of critical aspects in the life-cycles of the products. The studies will also form a database that can be used when making new LCAs. This knowledge should then be used when writing specifications of what to procure and setting criteria for procurement. The reports should be publicly available to allow reviews and discussions of results. To make the work more cost-effective, international co-operation should be sought. In addition, LCAs can also be performed as an integrated part of the acquisition process in specific cases.     

The Grand Objectives: A Framework for Prioritized Grouping of Environmental Concerns in Life-Cycle Assessment

The goal of life-cycle assessment (LCA) is to conduct an inventory of the flows of materials and energy attributable to an industrial product and then to calculate the impacts of those flows on the environment, over the entire product life cycle from premanufacture to end of 1ife. A related technique, streamlined life-cycle assessment (SLCA), attempts to preserve the breadth of perspective in that approach while performing assessments more efficiently. A common failing of both techniques is that recommendations for actions to improve the environmental responsibility of products have rarely been related in an intellectually rigorous fashion to the environmental concerns they purport to ameliorate. In this article l propose that a framework for the way in which these relationships can be established is by a decision-making process that begins with the "grand objectives," the common consensus of the vital goals for the maintenance and improvement of life on Earth. The grand objectives lead to the identification of crucial environmental concerns, and those, in turn, to determining societal activities that need to be examined. Actions related to those activities can then be designed to contribute to the achievement of the grand objectives. If and when such a consensus is established, LCAs and SLCAs can be undertaken with confidence that the actions they recommend will serve broad societal goals.     

Activity-Based Environmental Inventory Allocation

This article presents a generic method to assist product and process designers in measuring resource use and environmental discharges based on the relationships between process flow inputs and outputs and their activity levels. It combines activity-based costing from conventional accounting with life-cycle inventories. The method is demonstrated on four electronic assembly product and process designs. The demonstration exhibits the disaggregation and allocation of costs and effluents from various manufacturing operations. This activity-based environmental allocation approach may be integrated with inventory analysis-the first step in full and streamlined life-cycle assessments, design for environment evaluation methods, environmental management activities, and new production planning models that consider environmental impacts.     

The Importance of LCAs—Warts and All

Life-cycle assessment (LCA) is a new method for exploring the environmental implications of human action. Like all methods, it is analytically limited and consequently it must be used with caution. Recent papers have criticized LCA and caution against its use in all but a few narrow applications. Even while accepting many of these arguments, this article argues that LCAs, like other analytic frameworks used in the policy and planning domains, have important uses in shaping the processes by which both products and policies are designed. The arguments made against the use of LCAs omit comparisons to realistic appraisals of alternative and competing methods of environmental assessment.     

Method for Setting Environmental Targets in Product Development: Incorporating Use‐Phase Impact by Subsystem

In order to address environmental aspects during redesign, the product specification must include related targets that are reachable and challenging. To do so, this article presents a stepwise approach for combining benchmarking information and component impact, out of life cycle assessment (LCA) scaling. This approach requires allocating environmental impacts to each subsystem, which is not commonly done for some life cycle phases in LCAs, most particularly for use phases. This article includes a methodology for allocating such impacts. The underlying criterion is avoiding complex calculations, to make the method more agile. This methodology is presented in a full case study of a complex product: a knuckle boom crane. The case study results in the percentage of impact reduction needed to meet the market average or best competitors. In particular, the results show that the cylinders of the crane have a high contribution to environmental impact, not only because of their weight, but also because of the active power consumed to activate them.     

Application of uncertainty and variability in LCA

As yet, the application of an uncertainty and variability analysis is not common practice in LCAs. A proper analysis will be facilitated when it is clear which types of uncertainties and variabilities exist in LCAs and which tools are available to deal with them. Therefore, a framework is developed to classify types of uncertainty and variability in LCAs. Uncertainty is divided in (1) parameter uncertainty, (2) model uncertainty, and (3) uncertainty due to choices, while variability covers (4) spatial variability, (5) temporal variability, and (6) variability between objects and sources. A tool to deal with parameter uncertainty and variability between objects and sources in both the inventory and the impact assessment is probabilistic simulation. Uncertainty due to choices can be dealt with in a scenario analysis or reduced by standardisation and peer review. The feasibility of dealing with temporal and spatial variability is limited, implying model uncertainty in LCAs. Other model uncertainties can be reduced partly by more sophisticated modelling, such as the use of non-linear inventory models in the inventory and multi media models in the characterisation phase.     

Functional priorities in LCA and design for environment

Aim, Scope and Background  The interest in environmental questions has increased enormously during the last decade. Environmental protection has become an issue of strategic importance within the manufacturing industry and many companies are now working in the field of Design for Environment (DFE). The main purpose of DFE is to create products and services for achieving a sustainable society. Designers are widely believed to have a key role in adapting products to a sustainable society and one of the major instruments in the context of Design for Environment is Life Cycle Assessment (LCA). However, product development creates particular challenges for incorporating environmental issues that combine functional and environmental assessment. A natural and important part of product design is to define and analyse the functions of the product. Consequently, the functional unit in LCA is a core issue in DFE. Most recent research in DFE has focused on how to reduce the environmental impact of products throughout their life-cycle by addressing environmental aspects, while little attention has been given to the functionality of the product. Additionally, early product development phases, so called re-think phases, are considered to have the influence on major changes in products in general. These phases have thus the highest potential for changing products and product systems towards a sustainable development. Main Features  This paper discusses an extended functional representation in design for environment methods to evaluate sustainable design solutions, especially in early (re-think) phases of product design. Based on engineering-design science and several case studies, a concept has been developed describing how functional preferences can be visualised in design for environment and product development. In addition, the functional unit in LCA is discussed. The concept is called Functional Profile (FP) and is additionally exemplified in a case study on radio equipment. Discussion  The new functional characterisation concept helps identify functional priorities in design for environment. The Functional Profile is a structured, systematic and creative concept for identifying the necessary functions of a new product. The FP is envisioned to complement existing design for environment methods, not to replace them. Instead of being a product-development tool or method, the concept is an approach that increases understanding of inter-reactions between functional characteristics of products and their environmental characteristics, which furthermore facilitates trade-off decisions. One of the objectives behind the concept is to highlight the importance of balancing functional requirements and environmental impacts, presenting both the advantages and disadvantages of the product. Outlook  A second paper will be produced to complement the functional-environmental characterisation concept in early product development phase, presenting the environmental characterisation part and illustrating correlations between the functional and environmental sides.     

A Practical Method for Quantifying Eco-efficiency Using Eco-design Support Tools

Eco-efficiency at the product level is defined as product value per unit of environmental impact. In this paper we present a method for quantifying the eco-efficiency using quality function deployment (QFD) and life-cycle impact assessment (LCIA). These well-known tools are widely used in the manufacturing industry.
QFD, which is one of the methods used in product development based on consumer preferences, is introduced to calculate the product value. An index of the product value is calculated as the weighted average of improvement rates of quality characteristics. The importance of customer requirements, derived from the QFD matrix, is applied.
Environmental impacts throughout a product life cycle are calculated based on an LCIA method widely used in Japan. By applying the LCIA method of endpoint type, the endpoint damage caused by various life-cycle inventories is calculated. Willingness to pay is applied to integrate it into a single index.
Eco-design support tools, namely, the life-cycle planning (LCP) tool and the life-cycle assessment (LCA) tool, have already been developed. Using these tools, data required for calculation of the eco-efficiency of products can be collected. The product value is calculated based on QFD data stored in the LCP tool and the environmental impact is calculated using the LCA tool.
Case studies of eco-efficiency are adopted and the adequacy of this method is clarified. Several advantages of this method are characterized.     

Designing the ideal green product: Lca/SCLA in reverse

Traditional life-cycle assessment begins with a product and examines its environmental impacts throughout its life cycle. An alternative approach is to proceed in reverse: to examine the need that the product is designed to fulfill, to determine the minimal environmental impacts that could be engendered by filling that need, and thereby to design the “ideal green product” for the purpose. This approach, termed reverse life-cycle assessment (RLCA), is demonstrated by examining the environmental impacts attributable to a generic washing machine of current design, and then by reviewing other ways in which the provisioning of clean clothing may be accomplished. RLCA, as used here, is shown to encourage systems thinking and to identify opportunities for innovation in design and in marketing of environmentally-responsible products in ways that would be unlikely to arise from a traditional LCA.     

Fundamental Principles for CAD-based Ecological Assessments (9 pp)

Background Aims, and Scope. As products are, directly and indirectly, main sources for ecological impact, the overall enhancement of products' ecological behaviour is an important contribution to the protection of the Earth's biosphere. This is especially important in a world where the major economical system is based on a constant rise in industrial production, consumption, and disposal of products. The true ecological performance of a product can only be determined by consideration of the impact arising from the entire lifecycle, and by including all known impacts into the assessments. The state of technology provides a standardized framework for such life cycle assessments (LCA) in the ISO 14040 series (see ISO 1997), and numerous databases and software tools are available to support the conduction of LCA. To integrate ecological indicators into decisions of everyday product development, as natural as it is the case today with finite items, design, and costs, indicators based on a consideration of the product's entire life have to be generated with little effort and in short time. Methods This article describes the fundamental principles of a technology designed to integrate lifecycle information into common 3-dimensional product models, like the ones used within modern Computer Aided Design (CAD) systems. Thereby, ecological assessments can be effectively undertaken during product development, where most of the environmental lock-in of a product is defined (see Lewis et al. 2001). Overall effects of alterations in materials or other product properties can be assessed instantly, supporting on the spot decisions to reach an improved product design. Results Next to an information model that manages the product and process representation, the research on which this article is based also deals with the calculation of resulting indicators, database access to ecological indicators, a graphical user interface, and a synchronisation tool for the CAD system Pro/Engineer . The developed concepts have been implemented as a prototype software and validated in different stages. Conclusions The concepts described in this article are a foundation for tools that integrate ecological assessments into everyday product development, on the basis of 3-dimensional CAD systems. Reuse of existing CAD data, an improved understanding of the assessment structure by product developers, and an automated calculation of resulting indicators are approaches to largely enhance the efficiency of product-related ecological assessments.     

Estimating Environmental Behavior Without Performing a Life Cycle Assessment

Many authors have agreed on the interest of considering environmental concerns in the early stages of product development. However, most eco‐design tools are based on life cycle assessment principles and require a model to give information about the product's environmental performance. This modeling can have negative effects on team performance and on the potential for innovation, not to mention on the project's duration. Additionally, the model requires information that is not available in the early design stages. This article analyzes the potential of inferring conclusions about the life cycle stages with the highest impact by using similar products. From a database of previous products, environmental profile estimations are carried out, that is, the assessments of the contribution of each life cycle stage to the total impact and the variability of this measure. It is then possible to discard—or ensure consideration of—life cycle stages. Furthermore, the level of the conclusions is assessed on a five‐point scale. The proposed approach is applied to four case studies with different levels of abstraction and the relevance of the conclusions is assessed. The article resolves the problems regarding potential for estimating the distribution of the environmental impacts along the life cycle.     

Bottom-Up Life-Cycle:Assessment of Product Consumption in Belgium

The present study shows the results and methodology applied to the study of the identification of priority product categories for Belgian product and environmental policy. The main goal of the study was to gather insight into the consumption of products in Belgium and their related life-cycle environmental impacts. The conclusions of this project on the product categories with major environmental contributions can be used to start up working groups involving stakeholders and initiate detailed product studies on the impact reduction potential that could be achieved by means of implementing product policy measures. Several ways of assessing product category environmental impacts and the effects of policy measures have been developed; 'bottom-up' or 'market-life-cycle assessment' is one of these, and we tried this approach for the situation in Belgium. Simplified life-cycle assessment (LCA) studies were conducted for representative average products within each function-based product category and the results were multiplied with market statistics. Using this approach, we found that building construction, building occupancy, and personal transport are among the major categories for Belgium. The major drawbacks of this approach are the system-level limitations and the existence of a broad spectrum of nonharmonized methods and datasets from which a sound preliminary selection had to be made. Consequently, the retrieval and selection of data was very time consuming and due to this we had to accept some major limitations in the study design. Nevertheless, the study has contributed to the development of a methodology for market-LCA and elements that can be picked up in currently ongoing and future work. The study concludes that to improve the feasibility and acceptance of this type of study there is a need for the development of a harmonized methodology on market-LCA, policy-relevant impact indicators as well as a harmonized and stakeholder-agreed-upon LCA databases.     

Integration of Functional and Environmental Performance Design Decisions: A Mechanical Component Case Study

Product design-for-environment (DfE) has traditionally relied on life-cycle assessment (LCA) as a primary means of assessing environmental performance. To date, LCA has focused on static inventory and impacts of material streams during the stages of resource extraction, component manufacture, product use, and end of life at a high level of aggregation. Improvement analysis, though theoretically an important stage of LCA, is practically very challenging to implement using LCA alone. One reason for this is that the focus on detailed characterization of material streams does not facilitate a development of an understanding of the mechanistic relationship between design intent and material, manufacturing, and use-phase potential impacts. As the product development community transitions from sequential design to more streamlined concurrent design, interactive design tools are needed as a supplement to assessment tools in order to facilitate tradeoffs among environmental and other factors. This article presents an environmental analysis approach based on detailed process modeling which evaluates components from a functional design point of view. From a manufacturer's perspective, local potential effects in aggregate are often as important as global potential impacts. Furthermore, impacts often relate to explicit trade-offs between different life-cycle stages, such as production and use. In this article, the influence of functional design and manufacturing specifications (surface tolerance and finish) on localized potential impacts is illustrated through two different mechanical component (steel roller bearing and rotating shaft) case studies. Detailed analytical tools are key in enabling optimization and trade-offs by designers and process planners. The functional modeling approach is an important complement to LCA in providing a well-defined view of environmental performance.