An Empirical Examination of the Relationship between Lean Construction and Safety in the Industrialized Housing Industry

Proponents of Lean production claim that the implementation of Lean principles reduces accident rates. However, currently there is no empirical evidence in construction, in particular industrialized housing, on this hypothetical relationship. Current industry practice shows impressive results from using Lean tools in modular home manufacturing, yet its impact in employee safety outcomes is less understood. To explore this issue, this paper discusses the potential impacts of a specific concept used in Lean, continuous improvement (CI), on safety outcomes and shows results of an empirical analysis from an industry-wide survey of industrialized homebuilders on safety outcomes and CI programs. The analysis focused on 67 of 141 responses from builders in the U.S. that provided information on the use of CI programs. Nearly half of the survey respondents (62 homebuilders) use CI programs. The analysis showed that the presence of CI programs is associated with significantly lower injury incidence rates as compared to builders without CI programs. However, the presence or absence of CI programs did not result in significant differences in total OSHA-recordable cases, cases with restricted or transferred employees, total days lost, and days with restriction or transfer. Findings from this research will contribute to a better understanding of the applicability and potential benefits of Lean in the housing industry in terms of employee safety outcomes. Specific Lean strategies (CI programs) do appear to have some positive effects on OSHA incidence rates, which suggest that Lean may be beneficial not only for process improvement and waste reduction, but also for improving safety in the construction industry.