Mathematical models for determining the minimum level of voluntary safety investments for building projects

This study aims to investigate the minimum voluntary safety investment through optimization of total controllable safety costs for building projects. A correlational research study was designed to achieve the research aim. Data were collected using multiple techniques from 47 completed building projects in Singapore. The curves for describing the relationships between voluntary safety investment, total accident costs, accident frequency rate, and total controllable safety costs were developed using regression techniques. The optimization of voluntary safety investment was conducted using the extreme-value theorem with the objective of finding the minimum level of total controllable safety costs. The results show that the financially minimum voluntary safety investment varies with different levels of safety culture and project hazard. The models developed in this study can be used to estimate the minimum voluntary safety investment for building projects at different safety culture and project hazard levels. The findings of this study may provide the basis for financial decision making in managing construction safety for building contractors.