Examining health and safety through the Lean thinking lens: the case of the Nigerian construction industry

Health and safety issues in construction are a major source of concern across the world. Dealing with accidents and their aftermaths has a significant impact for construction firms as the prevention of such issues protects lives of workers and enhances efficiency and performances. In the Nigerian construction industry, this issue is even more substantial because many indigenous construction firms operating in the country do not value and prioritise risks and health and safety. As a result, accidents occur unnecessarily, which have a negative impact on the overall firms’ performance. Although the application of lean theory has been found to improve construction safety in other parts of the world, in Nigerian safety research, this problem has not been addressed fully and there is no safety framework available for accident prevention. The central aim of this research is to investigate how the adoption of lean practices can be the foundation for a safety system in the Nigerian construction industry. To this end, the thesis contains an extensive literature review on sociotechnical systems theory, being the umbrella theory adopted in this study to understand the problems associated with construction safety and explore how risks can be mitigated using lean practice. The thesis further focuses on three lean construction techniques: the 5S Methodology, Visual Management and the A3/PDCA and their deployment. The goal is to apply these tools to develop a lean safety framework that construction firms in Nigeria can make use of to mitigate accidents and their root causes. A qualitative study was conducted applying multiple case study design. In total, twenty-seven semi-structured interviews and non-participant observations were used to collect data from six indigenous construction companies in Nigeria: three small-scale and three medium scale companies. The collected data were thematically analysed. The study found five major root causes of accidents in the Nigerian construction industry: (i) lack of information, knowledge, and training; (ii) inability to identify or recognise hazards/unsafe conditions in the worksite before the start of tasks; (iii) identifying hazards/unsafe conditions and continuing to work without first eliminating the hazards/unsafe condition; (iv) management failure to provide safe work environment; and (v) negative behaviour and attitude towards safety by workers. The study also found that the 5S methodology, visual management and the A3/PDCA can be implemented in a safety system to mitigate accident root causes. This led to the development of a Lean Safety Framework (figure 10). Thus, the study has established that by providing a Lean Safety Framework (LSF), construction firms can improve health and safety performance and minimize the risks. Along with the developed framework, recommendations are provided for its use. This research makes two core contributions. It has contributed to theory development by expanding the use of sociotechnical systems theory, and by using the theory to detail how lean practice can be applied in safety systems to mitigate accident root causes in construction. It has contributed to the practice of lean and safety in Nigerian construction by developing a Lean Safety Framework that construction firms in the country can make use of to improve safety performance and save lives.