Measuring Complexity of Industrial Symbiosis Networks

Purpose - Industrial symbiosis networks (ISNs) are collections of long-term symbiotic relationships among firms, involving physical exchanges of materials and energy as well as the exchange of knowledge, concurrently providing environmental and economic benefits. Our aim is to investigate the complexity of ISNs adopting a similar approach to that developed by Hidalgo and Hausmann (2009) to measure the country economic complexity. In particular, we define a complexity index measuring the economic complexity of the firms involved in an ISN and provide some applications to real case studies.Design/methodology/approach - We define two matrixes, one identifying the waste each firm produces, and the other mapping the wastes each firm uses. Using these matrixes, we compute four indexes: 1) the diversity index of the firm producing wastes exchanged; 2) the diversity index of the firm using the wastes; 3) the ubiquity index of the waste exchanged in terms of number of the firms producing it; and 4) the ubiquity index of the waste exchanged in terms of number of the firms using them. A overall firm complexity measure is defined by using these indices.Originality/value - This paper made a methodological advance in the study of complexity within ISNs by applying an economic complexity approach. Complexity of ISNs is a fundamental property of the system, because it allows adaption and emergence useful to improve performance, which thus should be exploited rather than reduced. The approach proposed here allows the firm complexity to be assessed in a simple manner, without requiring high computational efforts like in other methods developed in the literature, but at the same time in a rigorous way, because the main driver of the economic complexity is taken into account.Practical implications - The study provides a rating of firms in a ISN based on the complexity index, which is useful to identify the most critical firms in terms of impact on the network resilience. The higher the firm complexity, the higher the risk that the firm unavailability due to a disruptive event can cause problem for the survival of the ISN.