Life cycle assessment and the resilience of product systems

Resilience is the capacity of systems to withstand and recover from disturbance, depends on the structure and architecture of a system, and plays a key role for the sustainability of complex systems. Despite its importance, resilience is not explicitly taken into account by studies of life cycle assessment (LCA), which main objective is determining the eco-efficiency of a product system with limited focus on its structure. The question is whether a product system which structure is improved or designed to be more resilient will result in being not only inefficient, but also eco-inefficient, when assessed by means of LCA. This study proposes a theoretical modelling approach to compare vulnerable and resilient product systems within the framework of LCA, consisting of assessment of disturbance and system expansion. Examples are provided where the theory is made operational. The structure of a vulnerable product system changes under disturbance: some processes are constrained and others are made necessary. In a resilient product system the number and type of processes do not change under conditions of disturbance, because some redundant disturbance-preventing activities are included. If this modelling approach is applied, resilient product systems appear not necessarily less eco-efficient than their vulnerable counterparts. This goes against the intuitive idea that optimizing a system for efficiency only will necessarily allow achieving eco-efficiency as well. This modelling approach is then critically discussed.