Product services systems (PSS) provide a promising opportunity for industries to propose both prosper and eco-friendly solutions to fulfill consumer needs. By shifting from traditional offer, comprised of physical products, to an integrated solution of product and services, it is assumed that PSS may reduce the environmental impact and provide benefits for the PSS provider and the consumer in economic and social ways. However, sustainability is not intrinsic characteristic of PSS. Operational methods and tools are needed to help companies develop such business models and support customer choices relating to PSS contracts. Although there are already well established assessment methods in literature, such as Life Cycle Assessment and Life Cycle Costing, there is still a lack of evidence from the particular field of PSS. Further on, most of existing methods and tools dealing with PSS assessment are based on qualitative parameters, which are subjective and hard to evaluate, and do not provide detailed views of the results.This paper analyses this piece of literature (i.e. relating to PSS assessment) to emphasize similarities and differences between available methods and tools. The aim is to identify the issues underpinning the development of methods for sustainable design in the particular case of PSS.