Tools for life cycle assessment

We provide guidance on how to perform life cycle assessment consistent with scientific standards and technical guidelines and also contribute to the development of tools and LCA software for the LCA practitioner. Targets are speed and precision.


Rules of thumb for system descriptions

Correct system description is crucial to obtain correct results. We have therefore focused on providing detailed guidance on how to ensure an appropriate description of the product to be assessed, and how to determine appropriately the processes to include in a product system. The guidance documents contain decision trees and default rules of thumb to be used in situations of limited knowledge. This speeds up the making of well-documented system descriptions. Some say that our scientific background report makes even better reading than the guidance documents. A more recent short introduction is found in Weidema B P, Ekvall T, Heijungs R (2009) · Guidelines for applications of deepened and broadened LCA. (Deliverable D18 of work package 5 of the CALCAS project). The method has now also been applied in the consequential system model of version 3 of the ecoinvent database. We have been deeply involved in the making of the ecoinvent consequential system model.

Precision tools

Assessments of the data and modelling uncertainty allows us to quickly focus further efforts on the main causes of uncertainty – not wasting time on issues of minor importance. We have developed the pedigree tool to estimate data uncertainty from data quality – a tool now used by the leading database provider Ecoinvent and integrated in the leading LCA software SimaPro. We have developed uncertainty estimates for input-output data, and use Monte Carlo simulations for uncertainty assessments and contribution analysis. The use of different tools for uncertainty analysis are described in the following publications: Reducing uncertainty in LCIAn integrated approach to uncertainty assessment in LCA, and Uncertainty reduction in consequential LCA models.

Impact assessment

We let you have the best of two worlds: Quick and unambiguous results at the push of a button, drawing together the complexity of social, environmental, and economic impacts into a single score, while still having the option of analysing each small contribution to the result in detail, and without sacrificing completeness.

Our ambition is to ensure that all important impact categories are included in our assessments. We have therefore developed impact assessment methods for nature occupation – covering the physical impacts of land use – and injuries (simplified methods are included in our Stepwise impact assessment method). Two important impact categories are still waiting to be included, namely noise and invasive alien species, both mainly related to transport activities. Our most recent achievement has been to place social and economic impacts in a life cycle context, using the same system delimitation, data collection procedures, and impact assessment endpoints for social and economic impacts as for environmental impacts. Our method thereby brings together the best of LCA and cost-benefit analyses.

The aggregation of all impact categories into a single score is based on the pioneering work of the Ecoindicator99 of PRé consultants, which operates with three endpoints (human health, ecosystem and resources). In our Stepwise impact assessment method, we have carried this work further, by finding a way to express the three endpoints in a single unit, namely QALYs (Quality-Adjusted Life Years). QALYs may alternatively be expressed in monetary units, thus allowing a full monetarisation of the results from life cycle assessments.

LCA software

We contribute to the development of LCA software. In particular, we recommend the SimaPro software to our customers, due to its ease of use, strong result analysis features, and its speedy calculation of the large matrices. Matrix calculation is a necessity to get the most out of the modern hybrid and input-output based databases. We develop tailor-made interfaces according to customer requirements as well as web-based and educational software. For an example of our web-applications, see our decision support tool Holiwast for LCA in waste management.