Work flow variability and labor productivity loss for construction projects

Labor productivity loss is one of the primary contributors to cost and schedule overruns that affect many construction projects. Quantifying lost labor productivity on construction projects is difficult and sometimes subjective and very approximate. A widely accepted way to quantify losses is the measured mile approach. In this research the measured mile and a variant, the baseline method, are analyzed and compared to a new, proposed statistical clustering method. This research explores applying a statistical clustering method to the measured mile and baseline calculation to inject objectivity in the analysis. The test on real data shows that the clustering method is more objective and therefore more convincing to both owners and contractors.; The research also explores the relationship between work flow variation and labor productivity. A case study of a pipe installation project was conducted to explore the correlation between work flow variation and labor productivity. 134 weeks of production data were collected and analyzed. It was found that labor productivity is correlated with Percent Plan Completed, a measure of work flow reliability.; Identifying and quantifying the benefit of improving work flow reliability can provide guidance for project managers to focus on the root causes of productivity loss in the planning stage. The research findings can also help consultants locate the causes and quantify responsibility of productivity loss in claims.