This paper seeks to provide a detailed procedural description for performing a consistency check for LCA as required by the ISO 14044 standard.
Consistency is defined as freedom from logical contradictions. The requirements of ISO 14044 are reviewed, and detailed guidance is provided for these and other related consistency issues.
Results and discussion
The procedural guidance reflects the iterative nature of the phases of LCA. Some inconsistencies can be of a more fundamental nature that does not allow a single consistent solution. Instead, more than one separately consistent solution can then be found and applied as separate “scenarios” presented to the decision maker with appropriate explanation of the fundamental differences of the scenarios, and their respective strengths and weaknesses for the decision context.
Revisiting and correcting inconsistencies can avoid most consistency problems. However, lack of resources may prohibit such adjustments, and the inconsistencies and their implications for the conclusions may then simply be stated and the conclusions modified accordingly.
This is a preview of subscription content, access via your institution.
Buy single article
Instant access to the full article PDF.
Price includes VAT (USA)
Tax calculation will be finalised during checkout.
This confusion is due to an unfortunate rewording during the 2006 revision (which was explicitly not intended to change the original requirements of the standards), in which the list in Clause 18.104.22.168.1 was given the status of a hierarchy, a status it did not have in the original ISO 14041 text.
In combined production, the amount of one co-product can be changed independently of the amount of the other co-products. In joint production, the amount of co-products cannot be changed independently, i.e. their amounts are always produced in the same fixed proportion.
Hunkeler D, Lichtenvort K, Rebitzer G (2008) Environmental life cycle costing. SETAC, Pensacola
ISO (2006) International Standard ISO 14044. Environmental management. Life cycle assessment. Requirements and guidelines. International Organization for Standardization, Geneva
ISO (2012) Technical report ISO 14049. Environmental management. Life cycle assessment. Illustrative examples on how to apply ISO 14044 to goal and scope definition and inventory analysis. International Organization for Standardization, Geneva
Laurent A et al (2018) Methodology review and detailed guidance for life cycle interpretation. Manuscript from a sub-group of the Task Force on cross-cutting issues under the SETAC-UNEP Life Cycle Initiative flagship project on ‘Global guidance for life cycle impact assessment’. Submitted to the International Journal of LCA. [Reference to be updated]
Pizzol M, Laurent A, Sala S, Weidema BP, Verones F, Koffler C (2017) Normalisation and weighting in life cycle assessment: quo vadis? Int J Life Cycle Assess 22(6):853–866
Sacchi R (2017) Example – heat recovery and system expansion. Published at www.consequential-lca.org
Sonnemann G, Vigon B (2011) Global Guidance Principles for Life Cycle Assessment Databases. UNEP/SETAC Life Cycle Initiative, Paris/Pensacola
Technical Report ISO (2006) International Standard ISO 14040. Environmental management. Life cycle assessment. Principles and framework. International Organization for Standardization, Technical Report
Weidema BP (2014) Has ISO 14040/44 failed its role as a standard for LCA? J Ind Ecol 18(3):324–326
Weidema BP (2016) Valuation procedures for product environmental footprint (PEF). Published as chapter 5 of Christiansen K (ed) (2016): Nordic environmental footprint seminar on LCA/PEF issues. http://www.nordic-pef.org/publications.html, http://lca-net.com/p/2551
Weidema BP (2017) Short procedural guideline to identify the functional unit for a product environmental footprint and to delimit the scope of product categories. Aalborg: 2.-0 LCA consultants. Report to the Nordic Council of Ministers. http://lca-net.com/p/2527
Weidema BP (2018) In search of a consistent solution to allocation of joint production. J Ind Ecol 22(2):252–262
Weidema BP, Wenzel H, Petersen CC, Hansen K (2004) The product, functional unit and reference flows in LCA. Miljøstyrelsen. (Environmental News 70), København
Weidema BP, Bauer C, Hischier R, Mutel C, Nemecek T, Reinhard J, Vadenbo CO, Wernet G (2013) Overview and Methodology Data quality guideline for the ecoinvent database version 3. Ecoinvent Report 1(v3). St. Gallen: The ecoinvent Centre
Weidema BP, Grbeš A, Brandão M (2015) The implicit boundary conditions of attributional and consequential LCA. Presentation to the ISIE Conference, Guildford, 7th–10th July 2015
Weidema BP, Pizzol M, Schmidt JH, Thoma G (2018) Attributional or consequential life cycle assessment: a matter of social responsibility. J Clean Prod 174:305–314
The development of this text was prompted by a request from the SETAC/UNEP Life Cycle Initiative Task Force on Interpretation, and was originally intended to be part of the article reporting from this Task Force (Laurent et al. 2018), but due to its degree of detail it was decided to provide it as a stand-alone article. I wish to express my gratitude for constructive comments from two anonymous reviewers.
Responsible editor: Serenella Sala
About this article
Cite this article
Weidema, B.P. Consistency check for life cycle assessments. Int J Life Cycle Assess 24, 926–934 (2019). https://doi.org/10.1007/s11367-018-1542-9
- Goal and scope
- Interpretation phase
- ISO 14044
- Procedural description