Effectiveness of craft time utilization in construction projects

Achieving efficient craft time utilization in the execution of construction projects is of great interest to project stakeholders. Craft time utilization assessment methods, such as work sampling and five-minute rating, measure the effectiveness of labour utilization, expose excessive non-productive time in the execution of construction activities, and reflect the soundness of workface planning. Onsite time utilization studies were conducted on 98 construction projects during the period 1972--2009. Statistic analyses were performed on the collected data to investigate the evolution of direct work rates and crew effectiveness over time, to gain understanding on craft time utilization patterns, and to identify improvement opportunities. The results of analyses suggest that, among other findings, the direct work ratio in construction projects and crew effectiveness in various construction activities have not improved during this period, and there is a statistically significant difference on crew effectiveness across different types of activities as well as in activities with different team size. The findings provide baselines to support the definition of craft time utilization targets in productivity improvement initiatives.