A survey of unresolved problems in life cycle assessment

Part 1: goal and scope and inventory analysis


Background, aims, and scope

Life cycle assessment (LCA) stands as the pre-eminent tool for estimating environmental effects caused by products and processes from ‘cradle to grave’ or ‘cradle to cradle.’ It exists in multiple forms, claims a growing list of practitioners, and remains a focus of continuing research. Despite its popularity and codification by organizations such as the International Organization for Standards and the Society of Environmental Toxicology and Chemistry, life cycle assessment is a tool in need of improvement. Multiple authors have written about its individual problems, but a unified treatment of the subject is lacking. The following literature survey gathers and explains issues, problems and problematic decisions currently limiting LCA’s goal and scope definition and life cycle inventory phases.

Main features

The review identifies 15 major problem areas and organizes them by the LCA phases in which each appears. This part of the review focuses on the first 7 of these problems occurring during the goal and scope definition and life cycle inventory phases. It is meant as a concise summary for practitioners interested in methodological limitations which might degrade the accuracy of their assessments. For new researchers, it provides an overview of pertinent problem areas toward which they might wish to direct their research efforts.

Results and discussion

Multiple problems occur in each of LCA’s four phases and reduce the accuracy of this tool. Considering problem severity and the adequacy of current solutions, six of the 15 discussed problems are of paramount importance. In LCA’s first two phases, functional unit definition, boundary selection, and allocation are critical problems requiring particular attention.

Conclusions and recommendations

Problems encountered during goal and scope definition arise from decisions about inclusion and exclusion while those in inventory analysis involve flows and transformations. Foundational decisions about the basis of comparison (functional unit), bounds of the study, and physical relationships between included processes largely dictate the representativeness and, therefore, the value of an LCA. It is for this reason that problems in functional unit definition, boundary selection, and allocation are the most critical examined in the first part of this review.


Environmental assessment Goal and scope definition Inventory analysis LCA methodology Life cycle assessment (LCA) Life cycle inventory analysis (LCI) Unresolved problems in LCA 



The presented material is based on work supported in part by NSF grants DMI-0600243 and DMI-0522116. We also gratefully acknowledge support from Georgia Tech’s Manufacturing Research Center and Woodruff School of Mechanical Engineering. John Reap and Scott Duncan gratefully acknowledge financial support provided by NSF grants DMI-0600243 and DMI-0522116, respectively. Felipe Roman acknowledges financial support given by Georgia Tech’s President’s Fellowship and the Goizueta Fellowship Program. All authors thank Valerie Thomas of Georgia Tech’s School of Industrial and Systems Engineering as well as IJLCA’s anonymous reviewers for their thoughtful comments and criticisms. Any opinions, finding, and conclusions or recommendations expressed in this paper are those of the authors and do not necessarily reflect the views of the US government and/or the authors’ parent institutions.


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Copyright information

© Springer-Verlag 2008

Authors and Affiliations

  • John Reap
    • 1
  • Felipe Roman
    • 1
  • Scott Duncan
    • 1
  • Bert Bras
    • 1
  1. 1.Sustainable Design and Manufacturing Program, Systems Realization Laboratory, The George W. Woodruff School of Mechanical EngineeringGeorgia Institute of TechnologyAtlantaUSA

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