Purpose - This paper aims to take a forensic approach to identify the causal mechanisms of rework in a structural steel supply chain. Rework is an area that has received limited attention, yet it is a major contributor to time and cost overruns in projects. Design/methodology/approach - The research uses an interpretative case study approach to gain an understanding about how and why rework occurred. To determine the causal variables of rework the traditional scientific concept of causality founded on the mono-causal model in the physical and biological sciences was subject to subtle changes, and adapted to a social context as construction projects are essentially complex social systems. In this instance causality was not considered to be linear, proportional or incremental, but multi-dimensional whereby each factor is interrelated and multi-causal in nature. Findings - The findings reveal that the cause of rework in this case was poor information flow and the absence of a quality focus. This was exacerbated by the sequential procurement process and fixed power structure of the contract, and as a consequence poor decision-making, communication, integration and co-ordination were experienced. Practical implications - The research has highlighted the need to re-design the structure of supply chains in construction projects, especially if information and communication technologies are to be effectively used. A conceptual model was developed from the case study findings to illustrate the interconnectedness of factors affecting rework. This model can be used by organisations for reducing the incidence of rework. Originality/value - The research has identified key variables that can contribute to the incidence of rework in projects. A pragmatic model for reducing the incidence of rework is proposed. The model that is propagated will be of use to practitioners and researchers working within project environments.