The development of the Functional Resonance Analysis Method (FRAM) has been motivated by the perceived limitations of fundamentally deterministic and probabilistic approaches to understand complex systems' behaviour. Congruent with the principles of Resilience Engineering, over recent years the FRAM has been progressively developed in scientific terms, and increasingly adopted in industrial environments with reportedly successful results. Nevertheless, a wide literature review focused on the method is currently lacking. On these premises, this paper aims to summarise all available published research in English about FRAM. More than 1700 documents from multiple scientific repositories were reviewed through a protocol based on the PRISMA review technique. The paper aims to uncover a number of characteristics of the FRAM research, both in terms of the method's application and of the authors contributing to its development. The systematic analysis explores the method in terms of its methodological aspects, application domains, and enhancements in qualitative and quantitative terms, as well as proposing potential future research directions.