Analysis of Workflow Variability and Its Impacts on Productivity and Performance in Construction of Multistory Buildings

The meeting of milestones presents a constant challenge in construction projects. One root cause behind this challenge is the presence of variability in the project workflow. In fact, impacts of variability at both the trade contractor level and project level remain difficult to manage. This paper aims to analyze impacts of variability in the workflow caused by rework and fluctuating work quantities. Toward this end, production data of two residential construction companies were collected, and a mixed method of mathematical and simulation modeling was used to analyze performance and productivity at both the trade and project levels. Performance metrics such as completion times, work-in-process levels, and delays were then measured in different real-life production scenarios. The findings clearly show that the workflow variability significantly downgrades performance metrics by causing inflated completion times, longer queues of uncompleted jobs, and excessive delays, resulting in productivity loss. The paper provides those who manage construction projects with recommendations on stabilizing the workflow in the interconnected network of trade contractors to improve productivity and performance. This study contributes to the body of knowledge in engineering management by enhancing the insight into workflow variability and its impacts on tangible performance measures. (C) 2015 American Society of Civil Engineers.