Novel approach of the integrated work & risk breakdown structure for identifying the hierarchy of fatal incident in construction industry

Given that the accident rate in the construction industry has remained higher than those in other industries for decades, various techniques and tools have been proposed to control construction hazards. The concepts of the work breakdown structure (WBS) and risk breakdown structure (RBS) have been presented to identify hazard hierarchies. With these tools, it is possible to subdivide and find work and risk units easily. Accordingly, this study suggests a novel approach called integrated WBS and RBS (i-WRBS) to identify such hierarchies in the construction industry. The research process involves four steps: (i) collection of data, (ii) classification of data, (iii) development of the i-WRBS, and (iv) conduct of a statistical analysis. Through the research process, i-WRBS is constructed with five levels, combining WBS up to level 4 and RBS at level 5. The i-WRBS approach consists of facility types (nine cases), project types (35 cases), work types (41 cases), and accident types (20 cases) arranged in a hierarchy. This study analyzes 5732 fatal incident cases from 2007 to 2016 in the construction industry in South Korea, with these incidents subdivided according to project, work, and accident types. The proposed i-WRBS method can show different hazard hierarchies depending on the project and work types. While the categories of ‘Industrial facility’ (facility type), ‘Factory’ (project type), ‘Steel Work’ (work type), and ‘Fall’ (accident type) have the largest numbers of fatal incident cases, ‘Explosion’ is the most critical accident type during a ‘Plant installation’ in a ‘Warehouse’ project. In order to identity differences in the proposed types and groups, a chi-square test, Welch's test, and then a post-hoc test (Games-Howell test) were conducted. The proposed i-WRBS method can contribute to identifying significant construction hazards considering the types of projects, work and accidents.