Decision making for sustainable development calls for scientific support in anticipating the possible consequences of decision alternatives and identifying the trade-offs between these alternatives. At the EU level, there has been a consistent movement toward the utilization of Sustainability Impact Assessments (SIA). First, the EU Strategy for Sustainable Development voiced the need to look at how EU policies contribute to sustainable development. Next, the European Commission committed to perform impact assessments of all proposed major initiatives. SIA can be used to study how factors such as policy, management, or technology development affect the sustainability of a sector or value chain and helps to inform decision makers about consequences of decision alternatives.
The Tool for Sustainability Impact Assessment (ToSIA) was developed to achieve a holistic assessment method for structuring sustainability questions as value chains of interlinked processes that enable evaluating the impacts of changes in these chains. To evaluate these changes, indicators of ecological, economic and social sustainability are utilised to describe different sustainability dimensions. Selecting the preferred alternative within these calculated differences in sustainability indicators may imply trade-offs and is enabled for example by the multi criteria analysis appended on top of ToSIA. The use of ToSIA is demonstrated through its application in numerous case studies conducted by various organizations and scholars.
This thesis presents the developed ToSIA from a methodological point of view, describing how the method is used. ToSIA is the first software implementation of a method that combines material flow based value chain analysis with indicators of different sustainability dimensions and harmonized system boundaries. ToSIA is a valid tool for evaluating consequences of the difficult decisions ahead that need to be made as we strive to enact a transition both to a 1.5 degree warming future, as well as a more sustainable humankind.