Sustainability Assessment of Product–Service Systems Using Flows between Systems Approach

The development of product–service systems (PSS) is currently considered a promising solution to the challenge of sustainability. Nevertheless, the sustainability of these systems has not been systematically assessed and there is a need to develop more guiding principles. In this work, an approach based on the flows between product and service systems is used to facilitate both the definition of PSS boundaries and the identification of links between the systems involved. In addition, the life cycle sustainability assessment (LCSA) method is applied to simultaneously quantify environmental, economic and social impacts. Two cases are analysed. First, the production process of cow´s milk, in which a veterinary service is required, is studied using data measured from a dairy farm. Next, the sustainability of a clothing retail service taking, into account that a construction product is involved in its creation stage, is evaluated. In each PSS specific life cycle, stages are analysed, a functional unit referred to both products and services is defined, and quantitative indicators are selected to assess each sustainability dimension. The category of workers is selected to evaluate social aspects. The relative incidence of each system is evaluated and the impacts of different factors on the PSS sustainability are analysed.