Development of Calculation Method for Full-Time Equivalent Workers per Man-Year to Improve Fatality Rate Estimation

The fatality rate in the construction industry is a key indicator for assessing safety management, with the number of workers being a critical factor in its estimation. Many countries rely on sampling inspections or assumptions to determine the number of workers, which can lead to inaccuracies in evaluating the fatality rate. In this study, we developed a method to calculate the full-time equivalent workers per man-year (FTEW_m·y) to more accurately estimate the fatality rate, taking into account building and work types using daily work reports (DWRs). The research process included six steps: (i) selecting a target project; (ii) establishing a database; (iii) developing the FTEW_m·y framework based on the DWR; (iv) validating the framework; (v) calculating the FTEW_m·y for residential building projects in the Republic of Korea; and (vi) applying the framework. The key findings included the following: the FTEW_m·y/USD for residential projects was 1.1 × 10⁻³ FTEW_m·y/USD, with the framework achieving an accuracy of 85.30% and an R² value of 92.92% through five-fold cross-validation. The FTEW_m·y for residential buildings in the Republic of Korea was 4.5 × 10⁷ FTEW_m·y, and the fatality rate was 0.011‱. This framework offers a more precise way of evaluating fatality rates by considering specific building and work types, improving safety management practices in the construction industry.