Life Cycle Assessment and Decision Making: Theories and Practices

Abstract: Life cycle assessment (LCA) has been in use to a varying extent since the late 1960s. The fact that LCA methodology needs further development is a frequently identified barrier to the further application of LCA. Consequently, the literature with suggestions for improving LCA methodology is extensive. This dissertation takes a different approach: it deals with the practice of LCA. The purpose has been to gain an understanding of the practice of LCA and to develop practice-based LCA methodology. A multidisciplinary approach, combining engineering and social sciences (especially, organisational theory), has been used.

The dissertation consists of 6 papers and an introduction. Employed research methods include theoretical discussions on LCA methodology, questionnaire surveys on the use of LCA in industry, and case studies on LCA projects in two Swedish companies. Three themes present in the 6 papers are explored in the introductory text: 1/ LCA methodology; 2/ the use of an LCA study in a project context; and 3/ the use of LCA in a company context.

By relating methodological approaches to application, two principally different types of LCA were identified: Life Cycle Accounting and Life Cycle Assessment. The former is based on a modelling strategy characterised as "full and complete", and is used for comparing the environmental burdens existing single-type products are made accountable for. The latter is "relevance-guided", and used for investigating consequences of a change. Another conclusion was that descriptions of LCA methodology would benefit from a greater distinction between the procedure and the model. The LCA model, being a "product" of the procedure, can be described according to certain fixed characteristics. Furthermore, strategies for conducting LCA studies are more diverse than approaches to modelling. As LCAs are used in a broad range of applications, LCA has been identified as a tool for learning rather than a tool for supporting single decisions. For the implementation of LCA activities in a company, the presence of an "LCA entrepreneur" is judged to be important. Identified barriers to application of LCA mainly concerned the level of understanding of LCA methodology and the process to gain commitment for LCAs.