Skip to main content
Log in

System boundaries and input data in consequential life cycle inventory analysis

  • Published:
The International Journal of Life Cycle Assessment Aims and scope Submit manuscript


Goal, Scope and Background

A consequential life cycle assessment (LCA) is designed to generate information on the consequences of decisions. This paper includes a comprehensive presentation of the consequential approach to system boundaries, allocation and data selection. It is based on a text produced within the SETAC-Europe working group on scenarios in LCA. For most of the methodological problems, we describe ideal methodological solutions as well as simplifications intended to make the method feasible in practice.


We compile, summarize and refine descriptions of consequential methodology elements that have been presented in separate papers, in addition to methodological elements and general conclusions that have not previously been published.

Results and Conclusions

A consequential LCA ideally includes activities within and outside the life cycle that are affected by a change within the life cycle of the product under investigation. In many cases this implies the use of marginal data and that allocation is typically avoided through system expansion. The model resulting from a consequential life cycle inventory (LCI) also includes the alternative use of constrained production factors as well as the marginal supply and demand on affected markets. As a result, the consequential LCI model does not resemble the traditional LCI model, where the main material flows are described from raw material extraction to waste management. Instead, it is a model of causal relationships originating at the decision at hand or the decision-maker that the LCI is intended to inform.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others


  • Azapagic A (1996) Environmental System Analysis: the Application of Linear Programming to Life Cycle Assessment — Volume 1. PhD thesis. University of Surrey, Guilford, UK

    Google Scholar 

  • Azapagic A, Clift R (1999) Allocation of environmental burdens in multiple-function systems. J Cleaner Prod 7 (2) 101–119

    Article  Google Scholar 

  • Baumann H (1998): Life Cycle Assessment and Decision Making — Theories and Practices. Ph.D thesis, Chalmers University of Technology, Gothenburg, Sweden

    Google Scholar 

  • Baumann H (1996): LCA Use in Swedish Industry. Int J LCA 1 (3) 122–126

    Article  Google Scholar 

  • Baumann H, Ekvall T, Eriksson E, Kullman M, Rydberg T, Ryding S-O, Steen B, Svensson G (1993): Environmental comparison between recycling/re-use and incineration/landfilling. FoU nr 79, REFORSK, Malmö, Sweden (in Swedish)

  • Berlin J (2002): Environmental life cycle assessment (LCA) of Swedish semi-hard cheese. Int Dairy J 12 (11) 939–953

    Article  Google Scholar 

  • Bouman M, Heijungs R, van der Voet E, van den Bergh JCJM, Huppes G (2000): Material flows and economic models: an analytical comparison of SFA, LCA and partial equilibrium models. Ecol Econ 32, 195–216

    Article  Google Scholar 

  • Cowell SJ (1998): Environmental Life Cycle Assessment of Agricultural Systems: Integration Into Decision-Making. Ph.D thesis. University of Surrey, Guildford, UK

    Google Scholar 

  • Curran MA, Mann M, Norris G (2001): Report on the International Workshop on Electricity Data for Life Cycle Inventories, US Environmental Protection Agency, Cincinnati, USA

    Google Scholar 

  • Ekvall T (1999a): System Expansion and Allocation in Life Cycle Assessment — With Implications for Wastepaper Management. Ph.D thesis, Chalmers University of Technology, Gothenburg, Sweden

    Google Scholar 

  • Ekvall T (1999b): Key methodological issues for Life Cycle Inventory Analysis of Paper Recycling. J Cleaner Prod 7 (4) 281–294

    Article  Google Scholar 

  • Ekvall T (2000): A Market-Based Approach to Allocation at Open-Loop Recycling. Resources, Conservation and Recycling 29, 91–109

    Article  Google Scholar 

  • Ekvall T (2003): Tools for consequential modelling. Poster presented at 13th SETAC-Europe Annual Meeting, Hamburg, Germany

    Google Scholar 

  • Ekvall T, Finnveden G (2001): Allocation in ISO 14041 — A Critical Review. J Cleaner Prod 9 (3) 197–208

    Article  Google Scholar 

  • Ekvall T, Tillman A-M (1997): Open-Loop Recycling: Criteria for Allocation Procedures. Int J LCA 2 (3) 155–162

    Article  Google Scholar 

  • Ekvall T, Person L, Ryberg A, Widheden J, Frees N, Nielsen PH, Pedersen BW, Wesnös M (1998): Life Cycle Assessment of Packaging Systems for Beer and Soft Drinks — Main Report. Miljøprojekt nr. 399, Danish Environmental Protection Agency, Copenhagen, Denmark

    Google Scholar 

  • Finnveden G, Ekvall T (1997): On the Usefulness of LCA in Decision-Making — the Case of Recycling vs. Incineration of Paper. Presentation Summaries, 5th LCA Case Studies Symposium, Brussels, Belgium, 9–17

    Google Scholar 

  • Frischknecht R (1997): Goal and Scope Definition and Inventory Analysis. In: Udo de Haes H, Wrisberg N (eds) Life Cycle Assessment: State-of-the-Art and Research Priorities. LCA Documents, Vol. 1, Ecoinforma Press Bayreuth and ecomed publishers, Landsberg, Germany, 59–88

    Google Scholar 

  • Grubbström RW (1977): Decision and gambling theory. Studentlitteratur, Lund, Sweden (in Swedish)

    Google Scholar 

  • Hauschild M, Wenzel H (1998): Environmental Assessment of Products — Vol. 2: Scientific Background. Chapman & Hall, London, UK

    Google Scholar 

  • Heijungs R (1997): Economic Drama and the Environmental Stage — Formal Derivation of Algorithmic Tools for Environmental Analysis and Decision Support from a Unified Epistemological Principle. Ph.D thesis, Leiden University, The Netherlands

    Google Scholar 

  • Heintz B, Baisnée P-F (1992): System Boundaries. In: Life Cycle Assessment — Workshop Report, Leiden, The Netherlands, 35–52

    Google Scholar 

  • Hofstetter P (1998): Perspectives in Life Cycle Impact Assessment — A Structured Approach to Combine Models of the Technosphere, Ecosphere and Valuesphere. Kluwer Academic Publishers, Dordrecht

  • ISO (1998): Environmental Management- Life Cycle Assessment — Goal and Scope Definition and Inventory Analysis. ISO 14041:1998(E) International Organisation of Standardisation, Geneva, Switzerland

  • Kåberger T, Karlsson R (1998): Electricity from a Competitive Market in Life-Cycle Analysis. J Cleaner Prod 6 (2) 103–109

    Article  Google Scholar 

  • Mattsson N, Unger T, Ekvall T (2001): Marginal Effects in a Dynamic System — The Case of the Nordic Power System. Presented to the International Workshop on Electricity Data for Life Cycle Inventories, Cincinnati, USA, 2001.10.23-25

  • Palmer K, Sigman H, Walls M (1997): The Cost of Reducing Municipal Solid Waste. J Environ Econom Manage 33, 128–150

    Article  Google Scholar 

  • Steen B (1999): A Systematic Approach to Environmental Priority Strategies in Product Development (EPS). Version 2000 — Models and Data of the Default Method. CPM report 1999:5, Chalmers University of Technology, Gothenburg, Sweden

    Google Scholar 

  • Tillman A-M (1998): Use of LCA and its Implications for LCA Methodology. Handout, Environmental Engineering Research Event 1998, New South Wales, Australia

    Google Scholar 

  • Tillman A-M (2000): Significance of Decision-Making for LCA Methodology. Environ Impact Assess Rev 20, 113–123

    Article  Google Scholar 

  • Weidema BP (1993): Development of a Method for Product Life Cycle Assessment with Special bl]References to Food Products (Summary). PhD thesis, Technical University of Denmark, Lyngby, Denmark

    Google Scholar 

  • Weidema B (2000): Avoiding Co-Product Allocation in Life Cycle Assessment. J Ind Ecol 4 (3) 11–33

    Article  CAS  Google Scholar 

  • Weidema BP (2003): Market Information in LCA. Environmental Project no. 863. Danish Environmental Protection Agency, Copenhagen, Denmark

    Google Scholar 

  • Weidema BP, Frees N, Nielsen P (1999): Marginal Production Technologies for Life Cycle Inventories. Int J LCA 4(1) 48–56

    Article  Google Scholar 

  • Weidema BP, Ekvall T, Pesonen H-L, Rebitzer G, Sonnemann GW, Spielmann M (2004): Scenarios in LCA. Society of Environmental Toxicology and Chemistry, Brussels/Pensacola (in press)

Download references

Author information

Authors and Affiliations


Corresponding author

Correspondence to Tomas Ekvall.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Ekvall, T., Weidema, B.P. System boundaries and input data in consequential life cycle inventory analysis. Int. J. LCA 9, 161–171 (2004).

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI: