Enhancing the practical implementation of life cycle sustainability assessment – proposal of a Tiered approach

Abstract Life cycle sustainability assessment has been claimed to be one of the most common methods for assessing sustainability of products and processes. It consists of the three methods life cycle assessment, life cycle costing and social life cycle assessment. However, the life cycle sustainability assessment framework is still under development and its application is still limited. This is substantiated not only by the lack of data and experience, but also by the proliferation of indicators provided by different institutions. Although indicators are available for the three sustainability dimensions, guidance for the indicator selection is missing. The bottleneck is not the lack of good indicators, but rather the lack of a clear indicator selection process. This appears to be one of the most crucial aspects as data availability, method development and interpretation of results heavily depend on this issue. Another obstacle for the practical implementation of life cycle sustainability assessment arises with the relatively high entrance level. Whereas, for the environmental dimension sufficient data and simplified methods are usually available, e.g. carbon footprint, the social and economic dimension are lacking of similar simplifications. Within this study a Tiered approach has been developed providing an indicator hierarchy and proposing a stepwise implementation concept. An indicator review has been performed according to the three criteria practicality, relevance and method robustness. Afterwards the indicators have been ranked in three tiers. The first tier (‘sustainability footprint’) focuses on indicators, which are characterized as easily applicable indicators and as relevant for production processes and on global scales. The second tier reflects current best practice indicators already used in case studies and preferred by institutions. The last tier aims at giving a comprehensive set of sustainability indicators, even if this level may not be applicable immediately. The Tiered approach may not solve all challenges within life cycle sustainability assessment, e.g. the question of how to solve the interpretation dilemma still remains; however it does support the practical application and further development of the framework through the stepwise implementation of sustainability indicators. The application and science related benefits of the Tiered approach result from the undergone comprehensive indicator review, which seems essential as a basis for further developments within the life cycle sustainability assessment framework, and from the proposed indicator hierarchy, which provides directions for further research. The created sustainability footprint facilitates the practical implementation of life cycle sustainability assessment, as the entrance barrier was lowered without neglecting any dimension of sustainability.