Improvement of the OHSMS to Increase Labor Productivity in the Production Area of a Construction Company, Santiago de Surco 2025.

Abstract

Background: Construction is among the most hazardous industries globally. In Peru, Law 29783 mandates occupational health and safety management systems, yet empirical evidence linking safety improvements to measurable labor productivity in construction small and medium enterprises remains limited, and economic returns are largely unexamined.
Materials & Methods: A pre-experimental pretest–posttest design was applied to 52 daily production orders from a construction firm in Santiago de Surco, Lima, Peru (pretest: August–September 2025; posttest: March–April 2026). The intervention was a five-dimensional safety system improvement. Efficiency (useful time / planned time), effectiveness (completed area / planned area), and their product—labor productivity—were compared using paired t-tests and the Wilcoxon signed-rank test after Kolmogorov–Smirnov normality assessment. Effect sizes and 95% confidence intervals were calculated. A 12-month cost–benefit analysis was also conducted.
Results: Mean productivity rose from 51.22% to 83.90%, efficiency from 79.05% to 97.44%, and effectiveness from 64.50% to 86.10% (all p < .001), with very large effect sizes. The cost–benefit analysis yielded a net present value of S/ 5,294.40, an internal rate of return of 8.53% per month, a benefit–cost ratio of 1.54, and payback in approximately seven months.
Conclusions: The findings indicate a positive temporal association between the five-dimensional safety system improvement and all three productivity indicators in this single-firm case study. The economic analysis supports the financial viability of safety investment under Peru’s regulatory framework. Replication using quasi-experimental designs across multiple firms is needed to establish generalizability.